High-Definition Multimedia Interface
Specification Version 1.4b
Hitachi Consumer Electronics Co., Ltd.
Panasonic Corporation.
Koninklijke Philips Electronics N.V.
Silicon Image, Inc.
Sony Corporation
Technicolor, S.A.
Toshiba Corporation
October 11, 2011
CONFIDENTIAL
High-Definition Multimedia Interface Specification
Version 1.4b
Preface
Notice
THIS SPECIFICATION IS PROVIDED “AS IS” WITH NO WARRANTIES WHATSOEVER,
EXPRESS OR IMPLIED, INCLUDING, WITHOUT LIMITATION, NO WARRANTIES OF
MERCHANTABILITY, NONINFRINGEMENT, FITNESS FOR ANY PARTICULAR PURPOSE, OR
ANY WARRANTY OTHERWISE ARISING OUT OF ANY PROPOSAL, SPECIFICATION, OR
SAMPLE.
Hitachi Consumer Electronics Co., Ltd., Panasonic Corporation, Koninklijke Philips Electronics
N.V., Silicon Image, Inc., Sony Corporation, Technicolor, S.A.., Toshiba Corporation and HDMI
Licensing, LLC disclaim all liability, including liability for infringement of any proprietary rights,
relating to use of information in this specification.
Copyright 2001-2011 by Hitachi Consumer Electronics Co., Ltd., Panasonic Corporation,
Koninklijke Philips Electronics N.V., Silicon Image, Inc., Sony Corporation, Technicolor, S.A.., and
Toshiba Corporation. All rights reserved. No license, express or implied, by estoppel or otherwise,
to any intellectual property rights is granted herein. Unauthorized use or duplication prohibited.
“HDMI” and all associated logos are trademarks of HDMI Licensing, LLC. Third-party trademarks
and servicemarks are property of their respective owners.
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High-Definition Multimedia Interface Specification
Version 1.4b
Document Revision History
1.4b
2011/10/11
Several minor editorials and clarifications (throughout).
1.4a
2010/03/04
Moved some 3D structures from Appendix H to 8.2.3 and 8.3.2.
Added 3D structure “Top-and-Bottom” (8.2.3)
Modified 3D video format requirements (8.2.3)
Added image size description in EDID (8.3.2)
Several minor editorial (throughout)
1.4
2009/06/05
Significant enhancements:
- Type D Connector (4.1.9.7, 4.1.9.8, 4.1.10.6)
- Type E Connector and Cable
(4.1.9.9, 4.1.9.10, 4.1.10.7, 4.1.10.8, 4.2.1, 4.2.3.2, 4.2.6)
- Audio Return Channel Overview (7.12)
- 3D and 4K x 2K video format (8.2.3, 8.3.2, Appendix H)
- HDMI Ethernet and Audio Return Channel(HEAC) features(Supplement 2)
Changed CEC supplement (see supplement 1 for details)
Changed “Reserved” to Utility Line (4.2.11)
Added Active, Passive and Converter cable types (4.2.6)
Moved Passive Cable characteristics to 4.2.6.
Added some features related to CEA-861 (6.3.2, 6.6, 6.7.2, 8.2, 8.3)
Several minor editorials (throughout)
1.3a
2006/11/10
Cable and Sink modifications for Type C (Table 4-28, 4.2.6)
Source termination recommendation (after Table 4-23)
Removed undershoot and max rise/fall time limits (4.2.4).
Modified slope of TP1 and TP2 eye diagrams (4.2.4, 4.2.5)
HDMI cable assembly AC-coupling support required (4.2.6)
CEC capacitance limits changed (4.2.10)
Valid range for RGB video quantization added (6.6)
Added audio sample rate exceptions for ACR (7.3, 7.3.1, 7.3.2)
Added Audio Rate Control Overview (7.11)
1.3
2006/06/22
Significant enhancements:
- Type C “Mini-Connector” (4.1.9.5, 4.1.9.6)
- Cable Categories 1 and 2 (4.2.6)
- Deep Color [4:4:4] (6.5, 8.3.2)
- Reference Cable Equalizer (4.2.3.2, 4.2.5, 4.2.6)
- Higher-speed single-link (4.1.2, 4.2.3,through 4.2.6, 8.3.2)
- xvYCC Enhanced Colorimetry (6.7.2.3)
- Gamut Metadata transmission (5.3.12, 6.7.2.4, Appendix E)
- DST audio format (5.3.10, 7.6.3)
- High-bitrate compressed audio formats (5.3.11, 7.2.4, 7.3.3, 7.6.2)
- Auto-Lipsync Correction feature (8.3.2, 8.9)
Updated normative reference from CEA-861-B to –D (1.2, throughout).
Updated Overview for new features (3)
Several minor editorial (throughout)
1.2a
2005/12/14
Changes to CEC supplement (see supplement for details)
Eliminated IOFF and made VOFF normative (4.2.4)
Changed CEC resistance to 5 ohms (4.2.10)
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High-Definition Multimedia Interface Specification
Version 1.4b
Clarified DVI device discrimination (8.3.5)
Several minor editorial (throughout)
1.2
2005/08/22
Removed limitations on Type A connector usage (4.1.2, 6.1)
Required new connector mechanical features, optional in 1.1 (4.1.9)
Required Sink support for future AC-coupled Sources (4.2.5)
Add note regarding maximum ratings of Sink (4.2.5)
Clarified Cable Assembly use of +5V Power (4.2.7)
Removed incorrect testing method for DDC capacitance (4.2.8)
Clarified when separate CEC lines on inputs are allowed (4.2.10)
Add maximum resistance spec for interconnected CEC line (4.2.10)
Remove CEC leakage current limit while in standby (4.2.10)
Relaxed YCBCR output requirement for RGB devices (6.2.3)
Added support for additional video formats (6.2.4, and 7.3.3, 8.2.1)
Corrected sample rate requirement from 1000 ppm to 1000 ppm (7.2.6)
Clarified use of Speaker Allocation Data Block (7.4)
Added support for One Bit audio (7.9, and throughout)
Clarified exception for 640x480p (VGA) declaration in EDID (8.3.6)
Loosened requirement for duplicated DTD declarations (8.3.6)
Added recommendation for setting Supports_AI (9.2)
Clarified the behavior of Repeater to Sink with Supports_AI (9.3.2)
Clarified rule for DVD-Audio ACP Packet transmission (9.3.5)
Additional minor editorial (throughout)
1.1
2004/05/20
Permitted multi-rate native format support on Type A Sinks (4.1.2)
Changed connector mechanical spec (4.1.9)
Changed connector electrical spec (4.1.7)
Removed CEC / +5V Power dependency for Source (4.2.7)
Loosened regulation requirements for +5V Power (4.2.7)
Made HPD voltages consistent with new +5V Power (4.2.9)
Clarified CEC connection requirements (4.2.10)
Restricted CTLx values allowed in non-Preamble periods (5.2.1)
Added new Packet Types (5.3.1)
Clarified InfoFrame Packet requirements (5.3.5)
Added ACP and ISRC Packet definitions and usage (5.3.7, 8.8, 9.3)
Specified recommended handling of non-Subpacket 0 CS blocks (7.1)
Clarified audio sample rate requirements (7.2.6)
Disallowed Layout 1 2-channel (7.6)
Clarified AVI transmission requirements (8.2.1)
Added extension fields and clarified HDMI VSDB (8.3.2)
Clarified DVI/HDMI device discrimination (8.3.5)
Clarified HPD behavior (8.5)
Clarified EDID values of Physical Addresses (8.7)
Made minor editorial changes (throughout)
1.0
2002/12/09
Initial Release
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Intellectual Property Statement
Hitachi Consumer Electronics Co., Ltd., Panasonic Corporation, Koninklijke Philips Electronics
N.V., Silicon Image, Inc., Sony Corporation, Technicolor, S.A.., and Toshiba Corporation each
may have patents and/or patent applications related to the High-Definition Multimedia Interface
Specification. These companies have made available to the industry an Adopter Agreement that
includes a limited, reciprocal patent license to certain of the electrical interfaces, mechanical
interfaces, signals, signaling and coding protocols, and bus protocols described in the mandatory
portions of the High-Definition Multimedia Interface Specification Release 1.4b published by HDMI
Licensing, LLC.
Contact Information
The URL for the HDMI Founders web site is: http://www.HDMI.org.
Contribution
Silicon Image, Inc has made a significant contribution to this standard by editing the specification
and developing the core technologies upon which this specification is based; including Transition
Minimized Differential Signaling (TMDS) technology.
Acknowledgement
HDMI founders acknowledge the concerted efforts of employees of Japan Aviation Electronics
Industry, Limited and Molex Japan, who have made a significant contribution to this standard by
developing the connector technology and the mechanical and electrical specifications for the
required plugs and receptacles.
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Version 1.4b
Table of Contents
PREFACE .....................................................................................................................................................II
NOTICE.........................................................................................................................................................II
DOCUMENT REVISION HISTORY ..................................................................................................................III
INTELLECTUAL PROPERTY STATEMENT ...................................................................................................... V
CONTACT INFORMATION ............................................................................................................................. V
CONTRIBUTION ........................................................................................................................................... V
ACKNOWLEDGEMENT.................................................................................................................................. V
1
INTRODUCTION .................................................................................................................................1
1.1
1.2
1.3
1.4
1.5
2
PURPOSE AND SCOPE .......................................................................................................................1
NORMATIVE REFERENCES ...............................................................................................................1
INFORMATIVE REFERENCES .............................................................................................................2
ORGANIZATION OF THIS DOCUMENT ................................................................................................2
USAGES AND CONVENTIONS ............................................................................................................3
DEFINITIONS.......................................................................................................................................5
2.1
2.2
2.3
CONFORMANCE LEVELS ..................................................................................................................5
GLOSSARY OF TERMS ......................................................................................................................5
ACRONYMS AND ABBREVIATIONS ...................................................................................................7
3
OVERVIEW ..........................................................................................................................................9
4
PHYSICAL LAYER ...........................................................................................................................11
4.1
CONNECTORS AND CABLES ...........................................................................................................11
4.1.1 Overview of Connectors and Cables ........................................................................................11
4.1.2 Connector Support Requirements.............................................................................................11
4.1.3 Dual-Link..................................................................................................................................12
4.1.4 Connector Pin Assignments......................................................................................................12
4.1.5 Contact sequence......................................................................................................................15
4.1.6 Connector Mechanical Performance........................................................................................16
4.1.7 Connector Electrical Characteristics .......................................................................................20
4.1.8 Connector Environmental Characteristics ...............................................................................22
4.1.9 Connector Drawings – Mating Interface Dimensions ..............................................................24
4.1.10
Cable Adapter Specification.................................................................................................44
4.2
ELECTRICAL SPECIFICATION..........................................................................................................53
4.2.1 TMDS Overview .......................................................................................................................53
4.2.2 TMDS System Operating Conditions........................................................................................54
4.2.3 TMDS Specification and Testing Overview ..............................................................................55
4.2.4 HDMI Source TMDS Characteristics.......................................................................................58
4.2.5 HDMI Sink TMDS Characteristics ...........................................................................................60
4.2.6 Cable Assembly TMDS Characteristics....................................................................................62
4.2.7 +5V Power Signal ....................................................................................................................71
4.2.8 DDC..........................................................................................................................................72
4.2.9 Hot Plug Detect Signal (HPD) .................................................................................................73
4.2.10
CEC Line ..............................................................................................................................73
4.2.11
Utility Line............................................................................................................................74
4.2.12
Robustness Requirements .....................................................................................................75
5
SIGNALING AND ENCODING........................................................................................................76
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5.1
OVERVIEW.....................................................................................................................................76
5.1.1 Link Architecture ......................................................................................................................76
5.1.2 Operating Modes Overview......................................................................................................77
5.2
OPERATING MODES .......................................................................................................................78
5.2.1 Control Period..........................................................................................................................78
5.2.2 Video Data Period ....................................................................................................................80
5.2.3 Data Island Period ...................................................................................................................80
5.3
DATA ISLAND PACKET DEFINITIONS .............................................................................................84
5.3.1 Packet Header ..........................................................................................................................84
5.3.2 Null Packet ...............................................................................................................................85
5.3.3 Audio Clock Regeneration Packet ............................................................................................86
5.3.4 Audio Sample Packet ................................................................................................................86
5.3.5 InfoFrame Packet .....................................................................................................................88
5.3.6 General Control Packet............................................................................................................89
5.3.7 Audio Content Protection Packet (ACP) ..................................................................................90
5.3.8 ISRC Packets ............................................................................................................................91
5.3.9 One Bit Audio Sample Packet...................................................................................................94
5.3.10
DST Audio Packet ................................................................................................................95
5.3.11
High-Bitrate (HBR) Audio Stream Packet............................................................................96
5.3.12
Gamut Metadata Packet .......................................................................................................96
5.4
ENCODING ...................................................................................................................................100
5.4.1 Serialization............................................................................................................................100
5.4.2 Control Period Coding ...........................................................................................................100
5.4.3 TERC4 Coding........................................................................................................................101
5.4.4 Video Data Coding .................................................................................................................101
6
VIDEO................................................................................................................................................105
6.1
OVERVIEW...................................................................................................................................105
6.2
VIDEO FORMAT SUPPORT ............................................................................................................105
6.2.1 Format Support Requirements................................................................................................105
6.2.2 Video Control Signals : HSYNC, VSYNC ...............................................................................106
6.2.3 Pixel Encoding Requirements.................................................................................................106
6.2.4 Color Depth Requirements .....................................................................................................106
6.3
VIDEO FORMAT TIMING SPECIFICATIONS ....................................................................................107
6.3.1 Primary Video Format Timings..............................................................................................107
6.3.2 Secondary Video Format Timings ..........................................................................................107
6.4
PIXEL-REPETITION ......................................................................................................................108
6.5
PIXEL ENCODINGS AND COLOR DEPTH ........................................................................................109
6.5.1 Pixel Encodings ......................................................................................................................109
6.5.2 Deep Color Pixel Packing ......................................................................................................110
6.5.3 Deep Color Mode / Phase Indication .....................................................................................113
6.5.4 Pixel Repetition ......................................................................................................................115
6.6
VIDEO QUANTIZATION RANGES ..................................................................................................116
6.7
COLORIMETRY .............................................................................................................................117
6.7.1 Default Colorimetry................................................................................................................117
6.7.2 Applicable Colorimetry Standards .........................................................................................117
6.7.3 Gamut-Related Metadata .......................................................................................................118
7
AUDIO................................................................................................................................................119
7.1
RELATIONSHIP WITH IEC 60958/IEC 61937................................................................................119
7.2
AUDIO SAMPLE CLOCK CAPTURE AND REGENERATION ..............................................................119
7.2.1 N parameter............................................................................................................................121
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7.2.2 CTS parameter........................................................................................................................121
7.2.3 Recommended N and Expected CTS Values ...........................................................................121
7.2.4 L-PCM and IEC 61937 Compressed Audio ACR ...................................................................124
7.2.5 One Bit Audio ACR.................................................................................................................124
7.2.6 DST Audio ACR......................................................................................................................124
7.3
AUDIO SAMPLE RATES AND SUPPORT REQUIREMENTS ...............................................................125
7.3.1 One Bit Audio Sample Rate Requirements .............................................................................126
7.3.2 DST Audio Sample Rate Requirements...................................................................................126
7.3.3 Video Dependency ..................................................................................................................127
7.4
CHANNEL / SPEAKER ASSIGNMENT .............................................................................................128
7.5
AUDIO, VIDEO SYNCHRONIZATION .............................................................................................128
7.6
AUDIO DATA PACKETIZATION .....................................................................................................128
7.6.1 One Bit Audio Packetization...................................................................................................130
7.6.2 High-Bitrate Audio Stream Packetization ..............................................................................131
7.6.3 DST Packetization ..................................................................................................................131
7.7
ERROR HANDLING (INFORMATIVE) .............................................................................................131
7.8
PACKET DELIVERY RULES ...........................................................................................................131
7.8.1 Audio Sample Packets ............................................................................................................131
7.8.2 Audio Clock Regeneration Packets ........................................................................................132
7.9
ONE BIT AUDIO USAGE OVERVIEW .............................................................................................132
7.10 DST USAGE OVERVIEW ..............................................................................................................132
7.11 AUDIO RATE CONTROL OVERVIEW .............................................................................................132
7.12 AUDIO RETURN CHANNEL OVERVIEW ........................................................................................133
8
CONTROL AND CONFIGURATION............................................................................................134
8.1
OVERVIEW...................................................................................................................................134
8.2
INFOFRAMES ...............................................................................................................................134
8.2.1 Auxiliary Video information (AVI) InfoFrame .......................................................................134
8.2.2 Audio InfoFrame ....................................................................................................................138
8.2.3 HDMI Vendor Specific InfoFrame .........................................................................................140
8.3
E-EDID DATA STRUCTURE .........................................................................................................150
8.3.1 CEA Extension........................................................................................................................150
8.3.2 HDMI Vendor-Specific Data Block (HDMI VSDB) ...............................................................150
8.3.3 Colorimetry Data Block..........................................................................................................157
8.3.4 Video Capability Data Block (VCDB) ....................................................................................158
8.3.5 DVI/HDMI Device Discrimination.........................................................................................159
8.3.6 Audio and Video Details.........................................................................................................159
8.4
ENHANCED DDC .........................................................................................................................160
8.4.1 Timing.....................................................................................................................................160
8.4.2 Data Transfer Protocols.........................................................................................................160
8.4.3 Segment pointer ......................................................................................................................160
8.4.4 Enhanced DDC Sink...............................................................................................................161
8.4.5 Enhanced DDC Source...........................................................................................................161
8.5
HOT PLUG DETECT SIGNAL .........................................................................................................161
8.6
CONSUMER ELECTRONICS CONTROL (CEC)................................................................................161
8.7
PHYSICAL ADDRESS ....................................................................................................................162
8.7.1 Overview.................................................................................................................................162
8.7.2 Physical Address Discovery ...................................................................................................162
8.7.3 Discovery Algorithm...............................................................................................................164
8.7.4 HDMI Sink Query...................................................................................................................164
8.8
ISRC HANDLING .........................................................................................................................164
8.9
AUTO LIPSYNC CORRECTION FEATURE .......................................................................................165
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8.9.1
8.9.2
8.9.3
8.9.4
9
Version 1.4b
EDID Latency Info..................................................................................................................165
Compensation .........................................................................................................................166
Supporting Dynamic Latency Changes...................................................................................167
Separate Audio and Video Paths ............................................................................................167
CONTENT PROTECTION..............................................................................................................168
9.1
RECOMMENDATION .....................................................................................................................168
9.2
HDCP IMPLEMENTATIONS ..........................................................................................................168
9.3
USAGE OF AUDIO CONTENT PROTECTION (ACP) PACKETS .........................................................168
9.3.1 Requirements for Sink.............................................................................................................168
9.3.2 Requirements for Repeater .....................................................................................................169
9.3.3 Application to Generic Audio .................................................................................................169
9.3.4 Application to IEC 60958-Identified Audio ............................................................................169
9.3.5 Application to DVD-Audio .....................................................................................................169
9.3.6 Application to Super Audio CD ..............................................................................................170
APPENDIX A
A.1
A.2
REPEATER FUNCTIONS ................................................................................................................172
E-EDID READ TIMING (INFORMATIVE).......................................................................................172
APPENDIX B
B.1
B.2
DEEP COLOR ADDITIONAL DETAIL ..................................................................178
STATE MACHINES ........................................................................................................................178
RECOMMENDED N AND EXPECTED CTS VALUES ........................................................................179
APPENDIX E
E.1
E.2
E.3
E.4
E.5
COMPATIBILITY WITH DVI ..................................................................................174
REQUIREMENT FOR DVI COMPATIBILITY ....................................................................................174
HDMI SOURCE REQUIREMENTS ..................................................................................................174
HDMI SINK REQUIREMENTS .......................................................................................................175
TYPE A TO DVI ADAPTER CABLE [INFORMATIVE]......................................................................175
TYPE B TO DVI ADAPTER CABLE [INFORMATIVE] ......................................................................177
APPENDIX D
D.1
D.2
TYPE B CONNECTOR USAGE................................................................................173
EXCEPTION TO AUDIO FORMAT SUPPORT REQUIREMENT ...........................................................173
HDMI DUAL-LINK ARCHITECTURE ............................................................................................173
APPENDIX C
C.1
C.2
C.3
C.4
C.5
REPEATER ..................................................................................................................172
GAMUT-RELATED METADATA............................................................................183
OVERVIEW...................................................................................................................................183
TRANSMISSION PROFILES ............................................................................................................183
GAMUT BOUNDARY DESCRIPTION...............................................................................................183
DATA PACKING ...........................................................................................................................186
EXAMPLE P0 DATA STRUCTURES ................................................................................................187
APPENDIX F
VIDEO SCALING AUTO-CONFIGURATION .......................................................190
APPENDIX G
RESERVED ..................................................................................................................191
APPENDIX H
3D VIDEO FORMATS EXTENSIONS .....................................................................192
H. 1
H. 2
H. 3
HDMI VENDOR SPECIFIC INFOFRAME EXTENSION ......................................................................192
3D VIDEO FORMATS STRUCTURE EXTENSION ...............................................................................195
HDMI VENDOR-SPECIFIC DATA BLOCK (HDMI VSDB) EXTENSION .........................................199
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SUPPLEMENT 1 CONSUMER ELECTRONICS CONTROL (CEC) ................................... CEC-I
SEE SUPPLEMENT FOR TABLE OF CONTENTS
SUPPLEMENT 2 HDMI ETHERNET AND AUDIO RETURN CHANNEL (HEAC) .......... HEAC-I
SEE SUPPLEMENT FOR TABLE OF CONTENTS
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Figures
Figure 3-1 HDMI Block Diagram ...............................................................................................9
Figure 4-1 Type A Receptacle Mating Interface Dimensions ..................................................24
Figure 4-2 Type A Plug Mating Interface Dimensions .............................................................26
Figure 4-3 Type A Receptacle and Plug Mated Condition ......................................................27
Figure 4-4 Type A Cable – Minimum Recommended Cable Bend .........................................27
Figure 4-5 Type B Receptacle Mating Interface Dimensions..................................................28
Figure 4-6 Type B Plug Mating Interface Dimensions.............................................................31
Figure 4-7 Type B Receptacle and Plug Mated Condition ......................................................31
Figure 4-8 Type C Receptacle Mating Interface Dimensions..................................................32
Figure 4-9 Type C Plug Mating Interface Dimensions ............................................................33
Figure 4-10 Type C Receptacle and Plug Mated Condition....................................................34
Figure 4-11 Type C Product Design Recommendations.........................................................34
Figure 4-12 Type D Receptacle Mating Interface Dimensions................................................35
Figure 4-13 Type D Plug Mating Interface Dimensions ..........................................................36
Figure 4-14 Type D Receptacle and Plug Mated Condition....................................................37
Figure 4-15 Type D Cable – Minimum Recommended Cable Bend.......................................37
Figure 4-16 Type E Receptacle Mating Interface Dimensions................................................38
Figure 4-17 Type E Plug Mating Interface Dimensions...........................................................40
Figure 4-18 Type E Product Design Recommendations.........................................................41
Figure 4-19 Type E Receptacle and Plug Mated Condition ....................................................41
Figure 4-20 Type A Relay Receptacle Mating Interface Dimensions......................................42
Figure 4-21 Type A Relay Receptacle Design Recommendations .........................................43
Figure 4-22 Conceptual Schematic for one TMDS differential pair.........................................53
Figure 4-23 Single-ended Differential Signal ..........................................................................53
Figure 4-24 Differential Signal.................................................................................................54
Figure 4-25 TMDS Link Test Points ........................................................................................54
Figure 4-26 TMDS Link Test Points for Automotive (Relay Connection) ................................54
Figure 4-27 Gain of Reference Cable Equalizer .....................................................................56
Figure 4-28 Gain of Reference Cable Equalizer for Automotive.............................................57
Figure 4-29 Balanced Source Test Load.................................................................................58
Figure 4-30 Eye Diagram Mask at TP1 for Source Requirements .........................................59
Figure 4-31 HDMI Sink Test Points .........................................................................................60
Figure 4-32 Eye Diagram Mask at TP2 for Sink Requirements ..............................................62
Figure 4-33 Cable Assembly Test Points ................................................................................63
Figure 4-34 Automotive CE Relay Cable Assembly Test Points (Relay Connection) .............63
Figure 4-35 Automotive Relay Cable Assembly Test Points (Relay Connection) ...................64
Figure 4-36 Category 1 Cable Attenuation Limits – Sufficient Condition ................................65
Figure 4-37 Category 2 Cable Attenuation Limits – Sufficient Condition ................................66
Figure 4-38 Passive equalizer Cable Attenuation Limits – Sufficient Condition .....................67
Figure 4-39 Passive equalizer Cable Phase measurement method (explanation).................68
Figure 4-40 Passive equalize Cable Phase Limits – Sufficient Condition ..............................68
Figure 4-41 Eye Diagram Mask at TP5 for CE Relay Cable...................................................70
Figure 5-1 HDMI Encoder/Decoder Overview ........................................................................76
Figure 5-2 Informative Example: TMDS periods in 720x480p video frame ............................77
Figure 5-3 TMDS Periods and Encoding ................................................................................81
Figure 5-4 Data Island Packet and ECC Structure .................................................................83
Figure 5-5 Error Correction Code generator ...........................................................................84
Figure 5-6 Example P0 Transmission Sequence....................................................................98
Figure 5-7 TMDS Video Data Encode Algorithm ..................................................................103
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Figure 5-8 TMDS Video Decode Algorithm ...........................................................................104
Figure 6-1 Default pixel encoding: RGB 4:4:4, 8 bits/component.........................................109
Figure 6-2 YCBCR 4:2:2 component ...................................................................................... 110
Figure 6-3 8-bit YCBCR 4:4:4 mapping .................................................................................. 110
Figure 6-4 YCBCR 4:2:2 with Pixel-Doubling ......................................................................... 116
Figure 7-1 Audio Clock Regeneration model ........................................................................120
Figure 7-2 Optional Implementation: Audio Sink...................................................................120
Figure 7-3 Example Audio Sample Timing (Informative) ......................................................130
Figure 8-1 extended resolution format ..................................................................................144
Figure 8-2 extended resolution format (detailed timing) .......................................................144
Figure 8-3 3D structure (Frame packing for progressive format)..........................................145
Figure 8-4 3D structure (Frame packing for interlaced format).............................................146
Figure 8-5 3D structure (Side-by-Side (Half)) .......................................................................146
Figure 8-6 3D structure (Top-and-Bottom) ............................................................................147
Figure 8-7 Detailed timing parameters..................................................................................148
Figure 8-8 CEC and DDC line connections ..........................................................................162
Figure 8-9 Typical HDMI cluster............................................................................................163
Figure 8-10 Addresses within an HDMI cluster.....................................................................163
Figure 8-11 ISRC/CCI and ISRC Status Handling ................................................................165
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Tables
Table 4-1 Relation of the Cable category and the Supported functions (except Type B) ....... 11
Table 4-2 Type A, Type E Connector Pin Assignment.............................................................12
Table 4-3 Type B Connector Pin Assignment..........................................................................13
Table 4-4 Type C Connector Pin Assignment .........................................................................14
Table 4-5 Type D Connector Pin Assignment .........................................................................15
Table 4-6 Connector Contact Sequence .................................................................................15
Table 4-7 Type A, Type C and Type D Plug and Receptacle Mechanical Performance .........16
Table 4-8 Type E Plug and Receptacle Mechanical Performance..........................................18
Table 4-9 Type E Cable Mechanical Performance..................................................................19
Table 4-10 Electrical Performance ..........................................................................................20
Table 4-11 Connector Environmental Performance ................................................................22
Table 4-12 Type E Connector Environmental Performance....................................................23
Table 4-13 Wire Categories.....................................................................................................44
Table 4-14 Type A-to-Type A Cable Wire Assignment.............................................................45
Table 4-15 Type A-to-Type B Cable Wire Assignment ............................................................46
Table 4-16 Type B to Type B Cable Wire Assignment ............................................................47
Table 4-17 Type C-to-Type C Cable Wire Assignment............................................................48
Table 4-18 Type C-to-Type A Cable Wire Assignment ............................................................49
Table 4-19 Type D-to-Type A Cable Wire Assignment ............................................................50
Table 4-20 Type E to Type E Cable Wire Assignment ............................................................51
Table 4-21 Type E-to-Type A Cable Wire Assignment ............................................................52
Table 4-22 Required Operating Conditions for HDMI Interface (see Figure 4-22) .................55
Table 4-23 Source DC Characteristics at TP1 ........................................................................58
Table 4-24 Source AC Characteristics at TP1.........................................................................59
Table 4-25 Sink Operating DC Characteristics at TP2............................................................61
Table 4-26 Sink DC Characteristics When Source Disabled or Disconnected at TP2 ...........61
Table 4-27 Sink AC Input Characteristics at TP2 ....................................................................61
Table 4-28 HDMI Sink Impedance Characteristics at TP2......................................................62
Table 4-29 Cable Assembly TMDS Parameters......................................................................65
Table 4-30 Cable Assembly TMDS Parameters......................................................................67
Table 4-31 Automotive Cable Assembly TMDS Parameters (Direct Connection) ..................69
Table 4-32 CE Relay Cable Assembly TMDS Parameters (Relay Connection) .....................70
Table 4-33 Automotive Relay Cable Assembly TMDS Parameters (Relay Connection) ........71
Table 4-34 +5V Power Pin Voltage .........................................................................................71
Table 4-35 Maximum Capacitance of DDC line ......................................................................72
Table 4-36 Maximum Capacitance of DDC line for Automotive ..............................................72
Table 4-37 Pull-up Resistance on DDC Lines.........................................................................72
Table 4-38 Required Output Characteristics of Hot Plug Detect Signal .................................73
Table 4-39 Required Detection Levels for Hot Plug Detect Signal .........................................73
Table 4-40 CEC line Electrical Specifications for all Configurations .......................................74
Table 4-41 Utility line Electrical Specifications (Recommendation) ........................................74
Table 5-1 Encoding Type and Data Transmitted .....................................................................78
Table 5-2 Preambles for Each Data Period Type....................................................................79
Table 5-3 TMDS Link Timing Parameters ...............................................................................80
Table 5-4 Extended Control Period Parameters .....................................................................80
Table 5-5 Video Leading Guard Band Values .........................................................................80
Table 5-6 Data Island Leading and Trailing Guard Band Values ............................................82
Table 5-7 Packet Header.........................................................................................................84
Table 5-8 Packet Types...........................................................................................................85
Table 5-9 Null Packet Header .................................................................................................85
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Table 5-10 Audio Clock Regeneration Packet Header............................................................86
Table 5-11 Audio Clock Regeneration Subpacket...................................................................86
Table 5-12 Audio Sample Packet Header ...............................................................................87
Table 5-13 Audio Sample Subpacket ......................................................................................87
Table 5-14 InfoFrame Packet Header .....................................................................................88
Table 5-15 InfoFrame Packet Contents ..................................................................................88
Table 5-16 General Control Packet Header ............................................................................89
Table 5-17 General Control Subpacket...................................................................................89
Table 5-18 ACP Packet Header ..............................................................................................90
Table 5-19 ACP Packet contents.............................................................................................90
Table 5-20 ISRC1 Packet Header...........................................................................................91
Table 5-21 ISRC1 Packet contents .........................................................................................92
Table 5-22 ISRC2 Packet Header...........................................................................................93
Table 5-23 ISRC2 Packet contents .........................................................................................93
Table 5-24 One Bit Audio Packet Header ...............................................................................94
Table 5-25 One Bit Audio Subpacket ......................................................................................95
Table 5-26 DST Audio Packet Header ....................................................................................95
Table 5-27 DST Audio Packet Body ........................................................................................96
Table 5-28 HBR Audio Stream Packet Header .......................................................................96
Table 5-29 Gamut Boundary Description Metadata Profiles ...................................................97
Table 5-30 Gamut Metadata Packet Header...........................................................................98
Table 5-31 Gamut Metadata Packet for P0 Transmission Profile ...........................................99
Table 5-32 Gamut Metadata Packet for P1 and Higher – 1st Packet of Sequence...............100
Table 5-33 Gamut Metadata Packet for P1 and Higher – Remaining Packets .....................100
Table 5-34 Control-signal Assignment ..................................................................................101
Table 5-35 Encoding Algorithm Definitions ...........................................................................102
Table 6-1 Color Depth (CD field) Values ............................................................................... 114
Table 6-2 Pixel Packing Phase (PP field) Values .................................................................. 115
Table 6-3 Video Color Component Ranges .......................................................................... 116
Table 7-1 Recommended N and Expected CTS for 32kHz ..................................................122
Table 7-2 Recommended N and Expected CTS for 44.1kHz and Multiples .........................123
Table 7-3 Recommended N and Expected CTS for 48kHz and Multiples ............................124
Table 7-4 Allowed Values for Channel Status bits 24 to 27...................................................126
Table 7-5 Max Sampling Frequency for 24-bit Video Format Timings* (Informative) ...........127
Table 7-6 Audio Packet Layout and Layout Value.................................................................129
Table 7-7 Valid Sample_Present Bit Configurations for Layout 0 .........................................129
Table 7-8 High Bitrate Audio Stream Packet Layout .............................................................131
Table 8-1 AVI InfoFrame Packet Header...............................................................................135
Table 8-2 AVI InfoFrame Packet Contents ............................................................................135
Table 8-3 Extended Colorimetry............................................................................................136
Table 8-4 VIC AVI InfoFrame Packet Contents .....................................................................137
Table 8-5 YCC Quantization Range ......................................................................................137
Table 8-6 Content Type .........................................................................................................137
Table 8-7 Audio InfoFrame Packet Header ...........................................................................139
Table 8-8 Audio InfoFrame Packet contents .........................................................................139
Table 8-9 LFE Playback Level Information ...........................................................................140
Table 8-10 HDMI Vendor Specific InfoFrame Packet Header...............................................141
Table 8-11 HDMI Vendor Specific InfoFrame Packet Contents ............................................141
Table 8-12 HDMI_Video_Format...........................................................................................141
Table 8-13 3D_Structure .......................................................................................................142
Table 8-14 HDMI_VIC for extended resolution transmission ................................................143
Table 8-15 3D transmission video formats ............................................................................147
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Table 8-16 HDMI-LLC Vendor-Specific Data Block (HDMI VSDB) .......................................152
Table 8-17 Content Type .......................................................................................................154
Table 8-18 Image_Size .........................................................................................................155
Table 8-19 3D_Structure_ALL ...............................................................................................156
Table 8-20 Colorimetry Data Block........................................................................................158
Table 8-21 Data Byte 3 Colorimetry Support flags................................................................158
Table 8-22 Data Byte 4 Colorimetry Metadata Support flags................................................158
Table 8-23 Video Capability Data Block (VCDB) ..................................................................159
Table 8-24 Quantization Range (Applies to YCC only) .........................................................159
Table 9-1 ACP_Type Dependent Fields for DVD-Audio Application .....................................170
Table 9-2 ACP_Type Dependent Fields for Super Audio CD Application .............................171
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Introduction
1.1
Purpose and Scope
Version 1.4b
This document constitutes the specification for the High-Definition Multimedia Interface (HDMI),
version 1.4b.
The High-Definition Multimedia Interface is provided for transmitting digital television audiovisual
signals from DVD players, set-top boxes and other audiovisual sources to television sets,
projectors and other video displays.
HDMI can carry high quality multi-channel audio data and can carry all standard and
high-definition consumer electronics video formats. Content protection technology is available.
HDMI can also carry control, status and data information in both directions.
This specification completely describes the interface such that one could implement a complete
transmission and interconnect solution or any portion of the interface. The underlying Transition
Minimized Differential Signaling (TMDS)-based protocol and associated electrical signaling is
described in detail. The mechanical specification of the connector and the signal placement within
the connector are described.
A device that is compliant with this specification is interoperable with other compliant devices
through the configuration and implementation provided for in this specification.
Mechanical, electrical, behavioral and protocol requirements necessary for compliance are
described for sources, sinks and cables.
1.2
Normative References
The following standards contain provisions that, through reference in this text, constitute normative
provisions of this standard. At the time of publication, the editions indicated were valid. All
standards are subject to revision, and parties to agreements based on this standard are
encouraged to investigate the possibility of applying the most recent editions of the standards
listed below. If the referenced standard is dated, the reader is advised to use the version specified.
CEA, CEA-861-D, “A DTV Profile For Uncompressed High Speed Digital Interfaces” 1
VESA, VESA E-EDID Standard, ENHANCED EXTENDED DISPLAY IDENTIFICATION DATA
STANDARD Release A, Revision 1, February 9, 2000
VESA, VESA E-DDC Standard, ENHANCED DISPLAY DATA CHANNEL STANDARD Version 1,
September 2, 1999
Philips Semiconductors, The I2C-bus Specification, Version 2.1, January 2000
ITU, ITU-R BT.601-5 Studio encoding parameters of digital television for standard 4:3 and
wide-screen 16:9 aspect ratios (October 1995)
1
All HDMI devices are required to comply with the requirements specified in CEA-861-D
except where specifically noted in this document. The CEA-861-D term “source” should be read
as “(HDMI) Source” and the terms “Display”, “Monitor” or “DTV Monitor” should be read as
“(HDMI) Sink”.
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ITU, ITU-R BT.709-5 Parameter values for the HDTV standards for production and international
programme exchange (2002)
IEC, IEC 60958-1, “Digital audio interface – Part 1: General”, First edition 1999-12
IEC, IEC 60958-3, “Digital audio interface – Part 3: Consumer applications”, Third edition 2006-05
IEC, IEC 61937, “Digital Audio - Interface for non-linear PCM encoded audio bitstreams applying
IEC 60958”, First edition 2000-04
IEC, IEC 61966-2-1/Amendment 1,”Multimedia systems and equipment - Colour measurement
and management - Part 2-1: Colour management - Default RGB colour space – sRGB”, 2003-01
IEC, IEC 61966-2-4: “Multimedia systems and equipment - Colour measurement and
management - Part 2-4: Colour management - Extended-gamut YCC colour space for video
applications – xvYCC”, January 2006
IEC, IEC 61966-2-5, “Multimedia systems and equipment - Colour measurement and
management - Part 2-5: Colour management - Optional RGB colour space – opRGB”.,Edition1.0
2007-11
DDWG, “Digital Visual Interface,” Revision 1.0, April 2, 1999 (DVI)
DVD Forum, “DVD Specifications for Read-Only Disc”, “Part 4: AUDIO SPECIFICATIONS”,
Version 1, March 1999.
DVD Forum, “DVD Specifications for Read-Only Disc”, “Part 4: AUDIO SPECIFICATIONS”,
Version-up Information (from 1.1 to 1.2), May 2000.
Digital Content Protection LLC, “High-bandwidth Digital Content Protection System Specification”,
Revision 1.4 (HDCP)
Royal Philips Electronics and SONY Corporation, “Super Audio CD System Description Version
2.0”
1.3
Informative References
The following documents contain information that is useful in understanding this standard. Some
of these documents are drafts of standards that may become normative references in a future
release of this standard.
ANSI/SMPTE, SMPTE Standard 170M (1999) for Television – Composite Analog Video Signal –
NTSC for Studio Applications
ANSI/SMPTE, SMPTE Standard 274M
ANSI/SMPTE, SMPTE Standard 296M
1.4
Organization of this document
This specification is organized as follows:
Chapter 1 introduces HDMI, describes the purpose and scope of this document, references,
organization of the document and usages and conventions.
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Chapter 2 defines terms and acronyms used throughout this document.
Chapter 3 provides a high-level overview of the operation of HDMI.
Chapter 4 describes the details of the Physical Layer of HDMI including basic electrical
specifications and mechanical specifications of cables and connectors.
Chapter 5 describes the Signaling and Encoding used by HDMI including descriptions of the
different periods and encoding types used to transmit audio, video, and control data types and
packet definitions for audio and auxiliary data.
Chapter 6 describes Video related issues including video format timings, pixel encodings
(RGB, YCBCR), colorimetry and corresponding requirements.
Chapter 7 describes Audio related issues including audio clock regeneration, placement of
audio samples within packets, packet timing requirements, audio sample rates and
requirements, and channel/speaker assignments.
Chapter 8 describes Control and Configuration functions, mechanisms and requirements,
including use of the E-EDID, and InfoFrames.
Chapter 9 describes the Content protection used for HDMI.
Appendix A describes the usage of Repeaters and Switches.
Appendix B describes restrictions related to the use of the Type B connector.
Appendix C describes DVI compatibility.
Appendix D describes additional details of Deep Color not covered in chapter 6, including
example state machines and details of audio transmission in a Deep Color mode.
Appendix E describes data structures and characteristics of gamut boundary descriptions,
used when transmitting video using xvYCC colorimetry.
Appendix F recommends a number of rules regarding a Sink’s indication of video format
support and automatic configuration of video output format for a Source.
Appendix G reserved.
Appendix H describes additional 3D video formats.
Supplement 1 describes use of the Consumer Electronics Control (CEC) line and protocol.
Supplement 2 describes the functionality and use of the HDMI Ethernet and Audio Return
Channel (HEAC).
1.5
Usages and Conventions
bit N
Bits are numbered in little-endian format, i.e. the least-significant bit of a
byte or word is referred to as bit 0.
D[X:Y]
Bit field representation covering bit X to bit Y (inclusive) of value or field
D.
0xNN
Hexadecimal representation of base-16 numbers are represented using
‘C’ language notation, preceded by ‘0x’.
0bNN
Binary (base-2) numbers are represented using ‘C’ language notation,
preceded by ‘0b’.
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NN
Version 1.4b
Decimal (base-10) numbers are represented using no additional prefixes
or suffixes.
Within this specification, any descriptions of data structures, values or sequences that occur on
the HDMI interface should be interpreted only as data structures, values and sequences that are
transmitted by the HDMI Source. Due to the possibility of errors during the transmission, these
items should not be construed as data structures, values or sequences that are guaranteed to be
detected by the HDMI Sink.
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2
Definitions
2.1
Conformance Levels
Version 1.4b
expected
A key word used to describe the behavior of the hardware or software in
the design models assumed by this specification. Other hardware and
software design models may also be implemented.
may
A key word that indicates flexibility of choice with no implied preference.
shall
A key word indicating a mandatory requirement. Designers are required
to implement all such mandatory requirements.
should
A key word indicating flexibility of choice with a strongly preferred
alternative. Equivalent to the phrase is recommended.
reserved fields
A set of bits within a data structure that are defined in this specification
as reserved, and are not otherwise used. Implementations of this
specification shall zero these fields. Future revisions of this specification,
however, may define their usage.
reserved values
A set of values for a field that are defined in this specification as
reserved, and are not otherwise used. Implementations of this
specification shall not generate these values for the field. Future
revisions of this specification, however, may define their usage.
2.2
Glossary of Terms
(Audio) Channel
Audio data intended to be delivered to a single audio speaker.
(Audio) Sample Clock
Original clock related to the audio input samples at the Source or the
generated clock used to time the output of audio samples.
BCH
Error correction technique named after the developers: Bose, Chaudhuri,
and Hocquenghem.
Byte
Eight bits of data.
CEA Extension
A 128 byte EDID 1.3-compatible extension block defined in CEA-861-D,
designed to allow declaration of audio formats, additional video formats
(beyond those in the base EDID structure) and other characteristics of
the Sink.
CEC Root (Device)
A device, generally a display (Sink) device, formally defined by the
following rule: A device that has no HDMI output or, a device that has
chosen to take the physical address 0.0.0.0 (see Section 8.7).
Compressed (Audio)
All audio formats carried by HDMI other than L-PCM and One Bit Audio.
Data Stream Disparity
Integer indicating “DC-offset” level of link. A positive value represents the
excess number of “1”s that have been transmitted. A negative value
represents the excess number of “0”s that have been transmitted.
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Direct Stream Transport An audio format which is a lossless compression of Direct Stream Digital
(DSD), as used in SuperAudio CD. DST is described in ISO/IEC 14496,
part 3, Amendment 6: Lossless coding of oversampled audio.
Downstream
In the direction of the primary audio and video data flow, i.e. towards the
Sink (e.g. display).
DVD-Audio
Disk format conforming to any version of “DVD Specifications for
Read-Only Disc”, “Part 4: AUDIO SPECIFICATIONS”.
(HDMI) Source
A device with an HDMI output.
(HDMI) Sink
A device with an HDMI input.
(HDMI) Repeater
A device with one or more HDMI inputs and one or more HDMI outputs.
Repeater devices shall simultaneously behave as both an HDMI Sink
and an HDMI Source.
InfoFrame
A data structure defined in CEA-861-D that is designed to carry a variety
of auxiliary data items regarding the audio or video streams or the
source device and is carried from Source to Sink across HDMI.
Multi-channel
Audio with more than 2 channels. Typically this term is applied to 6 (5.1)
channel streams. Also called surround formats.
One Bit Audio
1-bit Delta-Sigma modulated signal stream such as that used by Super
Audio CD.
Pixel
Picture Element. Refers to the actual element of the picture and the data
in the digital video stream representing such an element.
Pixel Encoding
Bit placement and sequencing for the components of a pixel for a
particular color space and chroma sampling.
Receiver
A component that is responsible for receiving the four differential TMDS
input pairs at the input to an HDMI Sink and converting those signals into
a digital output indicating a 24 bit, 12 bit, or 6 bit TMDS decoded word
and indicating the TMDS coding mode used to decode those bits. This
digital output may be contained within a semiconductor device or may be
output from a semiconductor device.
(TMDS) Character
A 10-bit TMDS-encoded value. One such value is carried on each of the
three data channels for each cycle of the TMDS clock.
Stereo
2 channel audio.
Stream
A time-ordered set of digital data originating from one Source and
terminating at zero or more Sinks. A stream is characterized by bounded
bandwidth requirements.
Super Audio CD
Disk format of “Super Audio CD System Description”, see
http://www.licensing.philips.com.
Tbit
Time duration of a single bit carried across the TMDS data channels.
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Tcharacter
Time duration of a single TMDS character carried across the TMDS data
channels. This is equal to 10Tbit .
Transmitter
A component that is responsible for driving the four differential TMDS
output pairs into an HDMI output and for clocking the data driven into
those four output pairs.
Video Field
The period from one VSYNC active edge to the next VSYNC active
edge.
Video Format
A video format is sufficiently defined such that when it is received at the
monitor, the monitor has enough information to properly display the
video to the user. The definition of each format includes a Video Format
Timing, the picture aspect ratio, and a colorimetry space.
Video Format Timing
The waveform associated with a video format. Note that a specific Video
Format Timing may be associated with more than one Video Format
(e.g., 720X480p@4:3 and 720X480p@16:9).
YCBCR
Digital representation of any video signal using one of several
luminance/color-difference color spaces.
2.3
Acronyms and Abbreviations
ACR
Audio Clock Regeneration
ANSI
American National Standards Institute
ARC
Audio Return Channel
AVI
Auxiliary Video Information
CEA
Consumer Electronics Association
CEC
Consumer Electronics Control
CTS
Cycle Time Stamp
DDC
Display Data Channel
DDWG
Digital Display Working Group
DST
Direct Stream Transport
DTD
Detailed Timing Descriptor
DTV
Digital Television
DVD
Digital Versatile Disc
DVI
Digital Visual Interface
E-DDC
Enhanced Display Data Channel
E-EDID
Enhanced Extended Display Identification Data
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ECC
Error Correction Code
EDID
Extended Display Identification Data
EIA
Electronic Industries Alliance
HDCP
High-bandwidth Digital Content Protection
HDMI
High-Definition Multimedia Interface
HDTV
High-Definition Television
HEAC
HDMI Ethernet and Audio Return Channel
HEC
HDMI Ethernet Channel
HPD
Hot Plug Detect
IEC
International Electrotechnical Commission
IEEE
Institute of Electrical and Electronics Engineers
ITU
International Telecommunications Union
L-PCM
Linear Pulse-Code Modulation
LSb
least significant bit
MPEG
Moving Picture Experts Group
MSb
most significant bit
N.C.
No connect.
PCB
Printed Circuit Board
Rx
Receiver
SMPTE
Society of Motion Picture & Television Engineers
STB
Set-Top Box
SVD
Short Video Descriptor
TERC4
TMDS Error Reduction Coding – 4 bit
TMDS
Transition Minimized Differential Signaling
Tx
Transmitter
VESA
Video Electronics Standards Association
VSDB
Vendor-Specific Data Block
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Version 1.4b
Overview
HDMI system architecture is defined to consist of Sources and Sinks. A given device may have
one or more HDMI inputs and one or more HDMI outputs. Each HDMI input on these devices shall
follow all of the rules for an HDMI Sink and each HDMI output shall follow all of the rules for an
HDMI Source.
As shown in Figure 3-1, the HDMI cable and connectors carry four differential pairs that make up
the TMDS data and clock channels. These channels are used to carry video, audio and auxiliary
data. In addition, HDMI carries a VESA DDC channel. The DDC is used for configuration and
status exchange between a single Source and a single Sink. The optional CEC protocol provides
high-level control functions between all of the various audiovisual products in a user’s environment.
The optional HDMI Ethernet and Audio Return Channel (HEAC) provides Ethernet compatible
data networking between connected devices and an Audio Return Channel in the opposite
direction from TMDS.
Video
Video
TMDS Channel 0
TMDS Channel 1
Audio
HDMI
Transmitter
Control/Status
TMDS Channel 2
TMDS Clock Channel
Display Data Channel (DDC)
CEC
CEC Line
HDMI
Receiver
Audio
Control/Status
EDID
ROM
CEC
Utility Line
HEAC
detect
HEAC
HPD Line
High / Low
Figure 3-1 HDMI Block Diagram
Audio, video and auxiliary data is transmitted across the three TMDS data channels. A TMDS
clock, typically running at the video pixel rate, is transmitted on the TMDS clock channel and is
used by the receiver as a frequency reference for data recovery on the three TMDS data channels.
At the source, TMDS encoding converts the 8 bits per TMDS data channel into the 10 bit
DC-balanced, transition minimized sequence which is then transmitted serially across the pair at a
rate of 10 bits per TMDS clock period.
Video data can have a pixel size of 24, 30, 36 or 48 bits. Video at the default 24-bit color depth is
carried at a TMDS clock rate equal to the pixel clock rate. Higher color depths are carried using a
correspondingly higher TMDS clock rate. Video formats with TMDS rates below 25MHz (e.g.
13.5MHz for 480i/NTSC) can be transmitted using a pixel-repetition scheme. The video pixels can
be encoded in either RGB, YCBCR 4:4:4 or YCBCR 4:2:2 formats.
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In order to transmit audio and auxiliary data across the TMDS channels, HDMI uses a packet
structure. In order to attain the higher reliability required of audio and control data, this data is
protected with a BCH error correction code and is encoded using a special error reduction coding
to produce the 10-bit word that is transmitted.
Basic audio functionality consists of a single IEC 60958 L-PCM audio stream at sample rates of
32kHz, 44.1kHz or 48kHz. This can accommodate any normal stereo stream. Optionally, HDMI
can carry such audio at sample rates up to 192KHz and with 3 to 8 audio channels. HDMI can also
carry an IEC 61937 compressed (e.g. surround-sound) audio stream at bit rates up to 24.576Mbps.
HDMI can also carry from 2 to 8 channels of One Bit Audio and a compressed form of One Bit
Audio called DST.
The DDC is used by the Source to read the Sink’s Enhanced Extended Display Identification Data
(E-EDID) in order to discover the Sink’s configuration and/or capabilities.
The Utility Line is used for extended optional features such as HEAC specified in Supplement 2.
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4
Physical Layer
4.1
Connectors and Cables
4.1.1
Overview of Connectors and Cables
A device’s external HDMI connection shall be presented via one of the five specified HDMI
connectors, Type A, Type B, Type C, Type D or Type E. This connector can be attached directly to
the device or can be attached via a cable adapter that is shipped with the device.
All five connectors carry all required HDMI signals, including a TMDS link. The Type B connector
is slightly larger and carries a second TMDS link, which is necessary to support very high
resolution displays using dual link. The Type C connector carries the same signals as the Type A
but is more compact and intended for mobile applications. The Type D connector carries the same
signals as the Type A but is more compact than Type C. The Type E connector carries the same
signals as the Type A and is intended for Automotive applications.
Cables are specified in two categories according to the supported clock frequency. Except for
Automotive applications, both categories of cables specified here can also support HEAC
applications after fulfilling the additional cable specifications in Supplement 2.
Table 4-1 Relation of the Cable category and the Supported functions (except Type B)
Electrical
Performance
Marketing name *
Type A – Type A/C/D
Type C – Type C
See 4.2.6
Standard
340MHz
Type A – Type A/C/D
Type C – Type C
See 4.2.6
High Speed
Category 1
with HEAC
74.25MHz
Type A – Type A/C/D
Type C – Type C
See 4.2.6 and
Supplement 2
Standard with Ethernet
Category 2
with HEAC
340MHz
Type A – Type A/C/D
Type C – Type C
See 4.2.6 and
Supplement 2
High Speed with
Ethernet
Type E – Type E
See 4.2.6
Cable
Assembly
Maximum
Clock
frequency
Category 1
74.25MHz
Category 2
Category 1
Automotive
4.1.2
74.25MHz
Cable Adapters
Type E – Type A Relay
receptacle
See 4.2.6
Type A – Type A
See 4.2.6
(only for Automotive
manufacturers)
Standard Automotive
Connector Support Requirements
All features and functions are equally available to all connectors except Type B and Type E.
*
from “Adopted Trademark and Logo Usage Guidelines”
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Version 1.4b
Dual-Link
To support DVI signals greater than 165Mpixels/sec, the dual-link capability of the Type B
connector shall be used. To support DVI signals less than or equal to 165Mpixels/sec, single-link
operation shall be used.
To support very high-speed HDMI signals, the dual-link capability of the Type B connector is
available. The single-link to dual-link crossover frequency for HDMI will be defined in a future
specification and will be greater than 340Mpixels/sec. Dual-link cannot be used for formats below
that crossover frequency.
4.1.4
Connector Pin Assignments
Table 4-2 Type A, Type E Connector Pin Assignment
PIN
Signal Assignment
PIN
Signal Assignment
1
TMDS Data2+
2
TMDS Data2 Shield
3
TMDS Data2–
4
TMDS Data1+
5
TMDS Data1 Shield
6
TMDS Data1–
7
TMDS Data0+
8
TMDS Data0 Shield
9
TMDS Data0–
10
TMDS Clock+
11
TMDS Clock Shield
12
TMDS Clock–
13
CEC
14
Utility
15
SCL
16
SDA
17
DDC/CEC Ground
18
+5V Power
19
Hot Plug Detect
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High-Definition Multimedia Interface Specification
Version 1.4b
Table 4-3 Type B Connector Pin Assignment
PIN
Signal Assignment
PIN
Signal Assignment
1
TMDS Data2+
2
TMDS Data2 Shield
3
TMDS Data2-
4
TMDS Data1+
5
TMDS Data1 Shield
6
TMDS Data1-
7
TMDS Data0+
8
TMDS Data0 Shield
9
TMDS Data0-
10
TMDS Clock+
11
TMDS Clock Shield
12
TMDS Clock-
13
TMDS Data5+
14
TMDS Data5 Shield
15
TMDS Data5-
16
TMDS Data4+
17
TMDS Data4 Shield
18
TMDS Data4-
19
TMDS Data3+
20
TMDS Data3 Shield
21
TMDS Data3-
22
CEC
23
Reserved (N.C. on device)
24
Reserved (N.C. on device)
25
SCL
26
SDA
27
DDC/CEC Ground
28
+5V Power
29
Hot Plug Detect
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High-Definition Multimedia Interface Specification
Version 1.4b
Table 4-4 Type C Connector Pin Assignment
PIN
Signal Assignment
1
TMDS Data2 Shield
2
TMDS Data2+
3
TMDS Data2-
4
TMDS Data1 Shield
5
TMDS Data1+
6
TMDS Data1-
7
TMDS Data0 Shield
8
TMDS Data0+
9
TMDS Data0-
10
TMDS Clock Shield
11
TMDS Clock+
12
TMDS Clock-
13
DDC/CEC Ground
14
CEC
15
SCL
16
SDA
17
Utility
18
+5V Power
19
Hot Plug Detect
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High-Definition Multimedia Interface Specification
Version 1.4b
Table 4-5 Type D Connector Pin Assignment
PIN
Signal Assignment
PIN
Signal Assignment
1
Hot Plug Detect
2
Utility
3
TMDS Data2+
4
TMDS Data2 Shield
5
TMDS Data2-
6
TMDS Data1+
7
TMDS Data1 Shield
8
TMDS Data1-
9
TMDS Data0+
10
TMDS Data0 Shield
11
TMDS Data0–
12
TMDS Clock+
13
TMDS Clock Shield
14
TMDS Clock–
15
CEC
16
DDC/CEC Ground
17
SCL
18
SDA
19
+5V Power
4.1.5
Contact sequence
Table 4-6 Connector Contact Sequence
Signals
Connection
Type A & C Connectors
Type B Connector
Type D Connector
Type E Connector
First Make
Connector shell
Connector shell
Connector shell
Connector shell
Second Make
Pins 1 - 17 and pin 19
Pins 1 - 27 and pin 29
Pins 1 – 18
Pins 1 - 19
Third Make
Pin18 (+5V Power)
Pin28 (+5V Power)
Pin19 (+5V Power)
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High-Definition Multimedia Interface Specification
4.1.6
Version 1.4b
Connector Mechanical Performance
Table 4-7 Type A, Type C and Type D Plug and Receptacle Mechanical Performance
Item
Test Condition
Requirement
Vibration
Amplitude : 1.52mm P-P or 147m/s2 {15G}
Appearance
No Damage
Contact
Resistance
Contact :
Change from initial value:
30 milliohms maximum.
Sweep time: 50-2000-50Hz in 20 minutes.
Duration : 12 times in each (total of 36 Times)
X, Y, Z axes.
Electrical load : DC100mA current shall be
Shell Part :
Change from initial value:
50 milliohms maximum.
Flowed during the test.
(ANSI/EIA-364-28 Condition III)
Shock
Pulse width: 11 msec.,
Waveform : half sine,
490m/s2{50G}, 3 strokes in each X.Y.Z. axes
Discontinuity
1 sec maximum.
Appearance
No Damage
Contact
Resistance
Contact :
Change from initial value:
30 milliohms maximum.
(ANSI/EIA-364-27, Condition A)
Shell :
Change from initial value:
50 milliohms maximum.
Durability
Measure contact and shell resistance after
Following.
Automatic cycling :
Type A: 10,000 cycles at 100 50 cycles per
hour
Discontinuity
1 sec maximum.
Contact
Resistance
Contact :
Change from initial value:
30 milliohms maximum.
Shell :
Change from initial value:
50 milliohms maximum.
Type C and Type D: 5,000 cycles at 100 50
cycles per hour
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High-Definition Multimedia Interface Specification
Item
Test Condition
Insertion /
Withdrawal
Force
Insertion and withdrawal speed :
Version 1.4b
Requirement
25mm/minute.
Withdrawal
force
(ANSI/EIA-364-13)
Type A:
9.8N {1.0kgf} minimum
39.2N {4.0kgf} maximum
Type C:
7N minimum
25N maximum
Type D:
5N minimum
25N maximum
and
after 5,000 cycles mating,
3N minimum
25N maximum
Cable Flex
100 cycles in each of 2 planes Dimension
Insertion force
44.1N {4.5kgf} maximum
Discontinuity
1 sec maximum.
Dielectric
Withstanding
Voltage and
Insulation
Resistance
Conform to item of
dielectric withstanding
voltage and insulation
resistance
appearance
Type D:
X = 3.7 x Cable Diameter.
(ANSI/EIA-364-41C, Condition I)
Wrenching
strength
Mated connectors,
apply perpendicular forces to plug at a 15 mm
distance from the edge of the receptacle
covered by test fixture.
0-20N: No plug or
receptacle damage.
20-40N: No receptacle
damage.
Perform this test using virgin parts.
Forces are to 4 directions (left, right, up, down).
Cable
Pull-Out
Axial load to the cable for 1 minute.
(ANSI/EIA-364-38c)
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Discontinuity
Type D:
40N minimum
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Page 17 of 201
High-Definition Multimedia Interface Specification
Version 1.4b
Table 4-8 Type E Plug and Receptacle Mechanical Performance
Item
Vibration
Test Condition
Requirement
Values for test-condition:
5.0Hz-0.00200g2/Hz
12.5Hz-0.24800g2/Hz
77.5Hz-0.00320g2/Hz
145.0Hz-0.00200g2/Hz
200.0Hz-0.01180g2/Hz
230.0Hz-0.00032g2/Hz
1000.0Hz-0.00002g2/Hz
{Grms=1.81}
Appearance
No Damage
Contact
Resistance
Contact :
Change from initial value:
30 milliohms maximum.
Shell Part :
Change from initial value:
50 milliohms maximum.
Duration: 8 hours in each (Total of 24
hours) X, Y, Z axis.
Discontinuity
1 sec maximum.
Appearance
No Damage
Contact
Resistance
Contact :
Change from initial value:
30 milliohms maximum.
Electrical load: 100mA DC current shall
be flowing during the test.
Shock
(SAE/USCAR-2 5.4.6)
Pulse width: 10msec
Waveform: half sine,
343m/s2{35G}, 10strokes in each X, Y, Z
axis
Shell :
Change from initial value:
50 milliohms maximum.
(SAE/USCAR-2 5.4.6)
Durability
Measure contact and shell resistance
after the following:
Discontinuity
1 sec maximum.
Contact
Resistance
Contact :
Change from initial value:
30 milliohms maximum.
Shell :
Change from initial value:
50 milliohms maximum.
Cycling: 10 cycles
(SAE/USCAR-2 5.1.7)
Drop
Drop onto a horizontal concrete surface
from a height of 1m.
Appearance
No Damage
Times: 3 times
(SAE/USCAR-2 5.4.8)
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High-Definition Multimedia Interface Specification
Version 1.4b
Item
Test Condition
Requirement
Connector-C
onnector
Insertion/
Withdrawal
Force
Insertion and withdrawal speed :
50mm/minute.
Insertion force
Withdrawal force
with the lock
completely
disengaged
Withdrawal force
with the lock
fully engaged
Withdrawal force
with the
secondary-lock
fully engaged
(SAE/USCAR-2 5.4.2)
Terminal-Con
nector
Withdrawal
Force
Withdrawal speed :
50mm/minute.
Lock
Disengage
ment Force
Disengagement speed :
50mm/minute.
70N maximum
70N maximum
100N minimum
90N minimum
(SAE/USCAR-2 5.4.1)
Disengageme
nt Force
50N maximum
Discontinuity
1 sec maximum.
Dielectric
Withstanding
Voltage and
Insulation
Resistance
Conform to item of
dielectric withstanding
voltage and insulation
resistance
(SAE/USCAR-2 5.4.2)
Cable Flex
25 cycles in each of 2 planes Dimension
X=6.4 x Cable Diameter.
(ANSI/EIA-364-41C,Condition I )
Table 4-9 Type E Cable Mechanical Performance
Item
Test Condition
Requirement
Thermal
Deformation
Tempurature:100 C
Overloading : 2N
Dielectric
Withstanding
Voltage
Conform to item of
dielectric withstanding
voltage
(ISO-6722,7-1)
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High-Definition Multimedia Interface Specification
4.1.7
Connector Electrical Characteristics
4.1.7.1
Electrical Performance
Version 1.4b
Table 4-10 Electrical Performance
Item
Test Condition
Requirement
Contact
Resistance
Mated connectors,
Initial Contact resistance
excluding conductor
resistance:
10 milliohms maximum .
(Target design value)
Contact : measure by dry circuit, 20 mVolts maximum.,10mA.
Shell : measured by open circuit, 5 Volts maximum ,100mA.
( ANSI/EIA-364-06B)
Dielectric
Strength
No Breakdown
Unmated connectors, apply
Type A/B/C/E :
500 Volts AC(RMS)
Type D
250 Volts AC(RMS)
:
between adjacent terminal or ground.
Mated connector, apply
Type A/B/C/E : 300 Volts AC(RMS.)
Type D
: 150 Volts AC(RMS.)
between adjacent terminal and ground.
(ANSI/EIA-364-20C, Method A)
Insulation
Resistance
Unmated connectors, apply 500 Volts DC between adjacent
terminal or ground.
100 megaohms minimum
(unmated)
(ANSI/EIA 364-21C)
Contact
Current Rating
Mated connectors, apply 150 Volts DC between adjacent
terminal or ground.
10 megaohms minimum
55 C, maximum ambient
Type A/B/C/E :
(mated)
0.5 A minimum
85 C, maximum temperature change
(ANSI/EIA-364-70A )
Type D:
0.3 A minimum
Applied
Voltage Rating
40 Volts AC (RMS.) continuous maximum, on any signal pin
with respect to the shield.
No Breakdown
Electrostatic
Discharge
Test unmated each connectors from 1 kVolt to 8 kVolts in 1
kVolt steps using 8mm ball probe.
No evidence of Discharge to
Contacts at 8 kVolts
Type E:
Test unmated each connectors from 1 kVolt to 8 kVolts
in 1 kVolt steps and 15 kVolts using 8mm ball probe.
(IEC-801-2)
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Type E :
No evidence of Discharge to
Contacts at 15 kVolts.
Page 20 of 201
High-Definition Multimedia Interface Specification
Version 1.4b
Item
Test Condition
Requirement
TMDS Signals Time
Domain Impedance
Rise time ≤ 200 psec (10%-90%).
Connector Area :
Type A/E: 100 ohms 15%
Type C/D: 100 ohms 25%
Signal to Ground pin ratio per HDMI designation.
Differential Measurement Specimen Environment
Impedance
= 100 ohms differential
Transition Area :
Type A /C/D:100 ohms 15%
Type E
:100 ohms 25%
Source-side receptacle connector mounted on a
controlled impedance PCB fixture.
Cable Area :
100 ohms 10%
(ANSI/EIA-364-108)
TMDS Signals Time
Domain Cross talk
FEXT
Rise time ≤ 200 psec (10%-90%).
Signal to Ground pin ratio per HDMI designation.
Type A
:
5% maximum
Differential Measurement Specimen Environment
Impedance
Type C/D/E : 10% maximum
= 100 ohms differential.
Source-side receptacle connector mounted on
controlled impedance PCB fixture.
Driven pair and victim pair.
(ANSI/EIA-364-90)
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High-Definition Multimedia Interface Specification
Version 1.4b
4.1.8
Connector Environmental Characteristics
4.1.8.1
Environmental Performance
Table 4-11 Connector Environmental Performance
Item
Test Condition
Requirement
Thermal
Shock
10 cycles of:
Appearance
No Damage
Contact
Resistance
Contact :
Change from initial
value: 30 milliohms
maximum.
a) -55°C for 30 minutes
b) +85°C for 30 minutes
(ANSI/EIA-364-32C, Condition I)
Shell Part :
Change from initial
value: 50 milliohms
maximum.
Humidity
A
Mate connectors together and perform the test as
follows.
Appearance
No Damage
Contact
Resistance
Duration : 4 cycles (96 hours)
Contact :
Change from initial
value: 30 milliohms
maximum.
Upon completion of the test, specimens shall be
conditioned at ambient room conditions for 24
hours, after which the specified measurements
shall be performed.
(ANSI/EIA-364-31B)
Shell :
Change from initial
value: 50 milliohms
maximum.
Temperature : +25 to +85°C
Relative Humidity : 80 to 95%
B
Unmated each connectors and perform the test as
follows.
Temperature : +25 to +85°C
Relative Humidity : 80 to 95%
Duration : 4 cycles (96 hours)
Upon completion of the test, specimens shall be
conditioned at ambient room conditions for 24
hours, after which the specified measurements
shall be performed.
(ANSI/EIA-364-31B)
Thermal
Aging
Mate connectors and expose to +105 ± 2°C for 250
hours. Upon completion of the exposure period, the
test specimens shall be conditioned at ambient room
conditions for 1 to 2 hours, after which the specified
measurements shall be performed.
(ANSI/EIA-364-17B, Condition 4, Method A)
Appearance
No Damage
Dielectric
Withstanding
Voltage and
Insulation
Resistance
Conform to item of
Dielectric Withstanding
Voltage and Insulation
Resistance
Appearance
No Damage
Contact
Resistance
Contact :
Change from initial
value: 30 milliohms
maximum.
Shell Part :
Change from initial
value: 50 milliohms
maximum.
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High-Definition Multimedia Interface Specification
Version 1.4b
Table 4-12 Type E Connector Environmental Performance
Item
Test Condition
Requirement
Thermal
Shock
100 cycles of:
a) －40 °C for 30 minutes
b) ＋100 °C for 30 minutes
Appearance
No Damage
Contact
Resistance
Contact :
Change from initial
value: 30 milliohms
maximum.
(SAE/USCAR-2 5.6.1)
Shell Part :
Change from initial
value: 50 milliohms
maximum.
Humidity
A
Mate connectors together and perform the test
as follows.
Temperature: －40 ~ +100 °C
Relative Humidity: 0 to 80%
Duration: 40 cycles (320 hours)
Appearance
No Damage
Contact
Resistance
Contact :
Change from initial
value: 30 milliohms
maximum.
(SAE/USCAR-2 5.6.2)
Shell :
Change from initial
value: 50 milliohms
maximum.
Unmate the connectors and perform the test as
follows.
Appearance
No Damage
Dielectric
Withstanding
Voltage and
Insulation
Resistance
Conform to item of
Dielectric Withstanding
Voltage and Insulation
Resistance
Mate connectors and expose to +100 °C for 1008
hours.
Appearance
No damage
(SAE/USCAR-2 5.6.3)
Contact
Resistance
Contact :
Change from initial
value: 30 milliohms
maximum.
B
Temperature: －40 ~ +100 °C
Relative Humidity: 0 to 80%
Duration: 40 cycles (320 hours)
(SAE/USCAR-2 5.6.2)
Thermal
Aging
Shell :
Change from initial
value: 50 milliohms
maximum.
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Page 23 of 201
High-Definition Multimedia Interface Specification
4.1.9
Version 1.4b
Connector Drawings – Mating Interface Dimensions
All dimensions in millimeters.
4.1.9.1
Type A Receptacle
The shell shall have springs for locking. Additional springs may be used for EMI
reduction.
The spring property for locking shall be activated by the locking hole of the plug
shell.
Figure 4-1 Type A Receptacle Mating Interface Dimensions
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Page 24 of 201
High-Definition Multimedia Interface Specification
Version 1.4b
DETAIL F
The form shown above is required. This feature will reduce the likelihood of damage
to the receptacle insulator under rough operation.
Figure 4-1–continued; Type A Receptacle, Detail F
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High-Definition Multimedia Interface Specification
4.1.9.2
Version 1.4b
Type A Plug
(See below)
DETAIL C
SECT B–B
SECT A–A
VIEW D
The dimension of *13.9mm (+0.04 / -0.05) (on main section) should be measured at
the point *7mm (on view D). The taper (on view D) shall be one degree max.
The shell should not have a dimple other than the ones for locking.
The triangle mark (on SECT B-B) is optional.
Figure 4-2 Type A Plug Mating Interface Dimensions
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High-Definition Multimedia Interface Specification
Version 1.4b
DETAIL E
The form shown above is required. This feature will reduce the likelihood of damage
to the receptacle insulator under rough operation.
Figure 4-2-continued; Type A Plug, Detail E
Figure 4-3 Type A Receptacle and Plug Mated Condition
It is recommended that products using Type A connectors be designed to ensure that cable bends
are not tighter than that shown in Figure 4-4.
Max 90mm
Figure 4-4 Type A Cable – Minimum Recommended Cable Bend
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Page 27 of 201
High-Definition Multimedia Interface Specification
4.1.9.3
Version 1.4b
Type B Receptacle
(See
below)
SECT A–A
DETAIL C
SECT F–F
SECT B–B
DETAIL E
The shell shall have springs for locking. Additional springs may be used for EMI
reduction.
The spring property for locking shall be activated by the locking hole of the plug
shell.
Figure 4-5 Type B Receptacle Mating Interface Dimensions
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High-Definition Multimedia Interface Specification
Version 1.4b
DETAIL G
The form shown above is required. This feature will reduce the likelihood of damage
to the receptacle insulator under rough operation.
Figure 4-5-continued; Type B Receptacle, Detail G
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High-Definition Multimedia Interface Specification
4.1.9.4
Version 1.4b
Type B Plug
(See below)
DETAIL C
DEPTH OF
LOCKING HOLE
SECT B–B
“VIEW D” NEXT PAGE
SECT A–A
The dimension of *21.2mm (+0.04 / -0.05) (on main section) should be measured at
the point *7mm (on view D). The taper (on view D) shall be one degree max.
The shell should not have a dimple other than the ones for locking.
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High-Definition Multimedia Interface Specification
Version 1.4b
DETAIL E
The form shown above is required. This feature will reduce the likelihood of damage
to the receptacle insulator under rough operation.
FRICTION LOCK TYPE
MECHANICAL LOCK TYPE
VIEW D
The spring property for locking should be activated
by the locking hole of the plug shell.
Figure 4-6 Type B Plug Mating Interface Dimensions
FULLY MATED
RECEPTACLE AND PLUG
SPRING PROPERTY
FOR LOCKING
Figure 4-7 Type B Receptacle and Plug Mated Condition
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High-Definition Multimedia Interface Specification
4.1.9.5
Version 1.4b
Type C Receptacle
SECT A-A
SECT B-B
DETAIL C
DETAIL D
DETAIL E
DETAIL F
The shell shall have spring for locking. Additional springs may be used for EMI reduction
The spring property for locking shall be activated by the locking hole of the plug shell.
Figure 4-8 Type C Receptacle Mating Interface Dimensions
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High-Definition Multimedia Interface Specification
4.1.9.6
Version 1.4b
Type C Plug
SECT A-A
DETAIL B
VIEW C
The shell should not have a dimple other than the ones for locking.
The cable should have a maximum diameter of 7mm
Figure 4-9 Type C Plug Mating Interface Dimensions
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High-Definition Multimedia Interface Specification
Version 1.4b
Figure 4-10 Type C Receptacle and Plug Mated Condition
It is recommended that products using Type C connectors be designed to ensure that cable bends
are not tighter than that shown in Figure 4-11. In addition, for strength, it is recommended that the
shell flange and the case be fixed with a screw and that the clearance between the connector and
the case be as narrow as possible.
Figure 4-11 Type C Product Design Recommendations
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Page 34 of 201
High-Definition Multimedia Interface Specification
4.1.9.7
Version 1.4b
Type D Receptacle
The shell shall have a spring for locking. Additional springs may be used for EMI
reduction.
The spring property for locking shall be activated by the locking hole of the plug shell.
Figure 4-12 Type D Receptacle Mating Interface Dimensions
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High-Definition Multimedia Interface Specification
4.1.9.8
Version 1.4b
Type D Plug
Figure 4-13 Type D Plug Mating Interface Dimensions
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High-Definition Multimedia Interface Specification
Version 1.4b
Figure 4-14 Type D Receptacle and Plug Mated Condition
Figure 4-15 Type D Cable – Minimum Recommended Cable Bend
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High-Definition Multimedia Interface Specification
4.1.9.9
Version 1.4b
Type E Receptacle
SECT C-C
SECT A-A
SECT E-E
SECT B-B
SECT D-D
Figure 4-16 Type E Receptacle Mating Interface Dimensions
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High-Definition Multimedia Interface Specification
SECT F-F
Version 1.4b
DETAIL G
DETAIL I
DETAIL H
・
・
The shell may be used for EMI reduction. It is the plug which may include the spring for
EMI.
The key shown above represents a standard key position. Position of the key may be
varied between * (5.4) and * (22.1), (The area shown by dotted lines ; DETAIL I). For
applications which require connector polarization, the key dimensions and location can be
designed within this range.
Figure 4-16-Continued : Type E Receptacle Mating Interface Dimensions
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Page 39 of 201
High-Definition Multimedia Interface Specification
Version 1.4b
4.1.9.10 Type E Plug
DETAIL C
SECT A-A
SECT B-B
Figure 4-17 Type E Plug Mating Interface Dimensions
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Page 40 of 201
High-Definition Multimedia Interface Specification
・
Version 1.4b
Minimum Recommended Cable Bend
It is recommended that products using Type E connectors be designed to ensure that cable
bends are not tighter than that shown in this Figure.
Figure 4-18 Type E Product Design Recommendations
Figure 4-19 Type E Receptacle and Plug Mated Condition
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High-Definition Multimedia Interface Specification
Version 1.4b
4.1.9.11 Type A Relay Receptacle
SECT A-A
DETAIL C
SECT D-D
SECT B-B
DETAIL E
DETAIL F
・
The shell shall have springs for locking. Additional springs may be used for EMI reduction.
・
The spring property for locking shall be activated by the locking hole of the plug shell.
・
The Performance shall be conformed to the specification of “Type A”.
・
The form shown above is required. This feature will reduce the likelihood of damage to the
receptacle insulator under rough operation.
Figure 4-20 Type A Relay Receptacle Mating Interface Dimensions
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High-Definition Multimedia Interface Specification
PLUG
Version 1.4b
Max. 90 mm
RELAY RECEPTACLE
Minimum Recommended Cable Bend
・
It is recommended that products using the Type A relay receptacle be designed to ensure
that cable bends are not tighter than that shown in the Figure.
Figure 4-21 Type A Relay Receptacle Design Recommendations
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Page 43 of 201
High-Definition Multimedia Interface Specification
4.1.10
Version 1.4b
Cable Adapter Specification
Table 4-13 Wire Categories
Category
A
B
C
D
N.C.
5V
HDMI Licensing, LLC
Description
TMDS Signal Wire
TMDS Shield
Control
Control Ground
No connect (no wire)
5 Volts Power Wire
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Page 44 of 201
High-Definition Multimedia Interface Specification
Version 1.4b
4.1.10.1 Type A Plug to Type A Plug
Table 4-14 Type A-to-Type A Cable Wire Assignment
Type A pin
Signal Name
Wire
Type A pin
1
TMDS Data2+
A
1
2
TMDS Data2 Shield
B
2
3
TMDS Data2–
A
3
4
TMDS Data1+
A
4
5
TMDS Data1 Shield
B
5
6
TMDS Data1–
A
6
7
TMDS Data0+
A
7
8
TMDS Data0 Shield
B
8
9
TMDS Data0–
A
9
10
TMDS Clock+
A
10
11
TMDS Clock Shield
B
11
12
TMDS Clock–
A
12
13
CEC
C
13
14
Utility
C
14
15
SCL
C
15
16
SDA
C
16
17
DDC/CEC Ground
D
17
18
+5V Power
5V
18
19
Hot Plug Detect
C
19
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4.1.10.2 Type A Plug to Type B Plug
Table 4-15 Type A-to-Type B Cable Wire Assignment
Type A pin
Pin Assignment
Wire
Type B pin
1
TMDS Data2+
A
1
2
TMDS Data2 Shield
B
2
3
TMDS Data2-
A
3
4
TMDS Data1+
A
4
5
TMDS Data1 Shield
B
5
6
TMDS Data1-
A
6
7
TMDS Data0+
A
7
8
TMDS Data0 Shield
B
8
9
TMDS Data0-
A
9
10
TMDS Clock+
A
10
11
TMDS Clock Shield
B
11
12
TMDS Clock-
A
12
13
CEC
C
22
15
SCL
C
25
16
SDA
C
26
17
DDC/CEC Ground
D
27
18
+5V Power
5V
28
19
Hot Plug Detect
C
29
14
No connect
N.C.
No connect
N.C.
23
No connect
N.C.
24
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4.1.10.3 Type B Plug to Type B Plug
Table 4-16 Type B to Type B Cable Wire Assignment
Type B pin
Pin Assignment
Wire
Type B pin
1
TMDS Data2+
A
1
2
TMDS Data2 Shield
B
2
3
TMDS Data2-
A
3
4
TMDS Data1+
A
4
5
TMDS Data1 Shield
B
5
6
TMDS Data1-
A
6
7
TMDS Data0+
A
7
8
TMDS Data0 Shield
B
8
9
TMDS Data0-
A
9
10
TMDS Clock+
A
10
11
TMDS Clock Shield
B
11
12
TMDS Clock-
A
12
13
TMDS Data5+
A
13
14
TMDS Data5 Shield
B
14
15
TMDS Data5-
A
15
16
TMDS Data4+
A
16
17
TMDS Data4 Shield
B
17
18
TMDS Data4-
A
18
19
TMDS Data3+
A
19
20
TMDS Data3 Shield
B
20
21
TMDS Data3-
A
21
22
CEC
C
22
25
SCL
C
25
26
SDA
C
26
27
DDC/CEC Ground
D
27
28
+5V Power
5V
28
29
Hot Plug Detect
C
29
23
No Connect
N.C.
24
No Connect
N.C.
No Connect
N.C.
23
No Connect
N.C.
24
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4.1.10.4 Type C Plug to Type C Plug
Table 4-17 Type C-to-Type C Cable Wire Assignment
Type C pin
Signal Name
Wire
Type C pin
1
TMDS Data2 Shield
B
1
2
TMDS Data2+
A
2
3
TMDS Data2-
A
3
4
TMDS Data1 Shield
B
4
5
TMDS Data1+
A
5
6
TMDS Data1-
A
6
7
TMDS Data0 Shield
B
7
8
TMDS Data0+
A
8
9
TMDS Data0-
A
9
10
TMDS Clock Shield
B
10
11
TMDS Clock+
A
11
12
TMDS Clock-
A
12
13
DDC/CEC Ground
D
13
14
CEC
C
14
15
SCL
C
15
16
SDA
C
16
17
Utility
C
17
18
+5V Power
5V
18
19
Hot Plug Detect
C
19
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4.1.10.5 Type C Plug to Type A Plug
Table 4-18 Type C-to-Type A Cable Wire Assignment
Type C pin
Signal Name
Wire
Type A pin
1
TMDS Data2 Shield
B
2
2
TMDS Data2+
A
1
3
TMDS Data2-
A
3
4
TMDS Data1 Shield
B
5
5
TMDS Data1+
A
4
6
TMDS Data1-
A
6
7
TMDS Data0 Shield
B
8
8
TMDS Data0+
A
7
9
TMDS Data0-
A
9
10
TMDS Clock Shield
B
11
11
TMDS Clock+
A
10
12
TMDS Clock-
A
12
13
DDC/CEC Ground
D
17
14
CEC
C
13
15
SCL
C
15
16
SDA
C
16
17
Utility
C
14
18
+5V Power
5V
18
19
Hot Plug Detect
C
19
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4.1.10.6 Type D Plug to Type A Plug
Table 4-19 Type D-to-Type A Cable Wire Assignment
Type D pin
Signal Name
1
Hot Plug Detect
C
19
2
Utility
C
14
3
TMDS Data2+
A
1
4
TMDS Data2 Shield
B
2
5
TMDS Data2-
A
3
6
TMDS Data1+
A
4
7
TMDS Data1 Shield
B
5
8
TMDS Data1-
A
6
9
TMDS Data0+
A
7
10
TMDS Data0 Shield
B
8
11
TMDS Data0–
A
9
12
TMDS Clock+
A
10
13
TMDS Clock Shield
B
11
14
TMDS Clock–
A
12
15
CEC
C
13
16
DDC/CEC Ground
D
17
17
SCL
C
15
18
SDA
C
16
19
+5V Power
5V
18
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4.1.10.7 Type E Plug to Type E Plug
Table 4-20 Type E to Type E Cable Wire Assignment
Type E pin
Signal Name
Wire
Type E pin
1
TMDS Data2+
A
1
2
TMDS Data2 Shield
B
2
3
TMDS Data2–
A
3
4
TMDS Data1+
A
4
5
TMDS Data1 Shield
B
5
6
TMDS Data1–
A
6
7
TMDS Data0+
A
7
8
TMDS Data0 Shield
B
8
9
TMDS Data0–
A
9
10
TMDS Clock+
A
10
11
TMDS Clock Shield
B
11
12
TMDS Clock–
A
12
13
CEC
C
13
14
Utility
C
14
15
SCL
C
15
16
SDA
C
16
17
DDC/CEC Ground
D
17
18
+5V Power
5V
18
19
Hot Plug Detect
C
19
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4.1.10.8 Type E Plug to Type A Relay Receptacle
Table 4-21 Type E-to-Type A Cable Wire Assignment
Type E pin
Signal Name
Wire
Type A pin
1
TMDS Data2+
A
1
2
TMDS Data2 Shield
B
2
3
TMDS Data2–
A
3
4
TMDS Data1+
A
4
5
TMDS Data1 Shield
B
5
6
TMDS Data1–
A
6
7
TMDS Data0+
A
7
8
TMDS Data0 Shield
B
8
9
TMDS Data0–
A
9
10
TMDS Clock+
A
10
11
TMDS Clock Shield
B
11
12
TMDS Clock–
A
12
13
CEC
C
13
14
Utility
C
14
15
SCL
C
15
16
SDA
C
16
17
DDC/CEC Ground
D
17
18
+5V Power
5V
18
19
Hot Plug Detect
C
19
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4.2
Version 1.4b
Electrical Specification
Some timing parameter values in this specification are based on the clock rate of the link while
others are based on absolute values. For scalable timing parameters based on the TMDS clock
rate, the time period of the clock is denoted as ‘TMDS character time’, or Tcharacter. One tenth of the
character time is called the bit time, or Tbit. The bit time is also referred to as one Unit Interval in
the jitter and eye diagram specifications.
Schematic diagrams contained in this chapter are for illustration only and do not represent the only
feasible implementation.
4.2.1
TMDS Overview
The conceptual schematic of one TMDS differential pair is shown in Figure 4-22. TMDS
technology uses current drive to develop the low voltage differential signal at the Sink side of the
DC-coupled transmission line. The link reference voltage AVcc sets the high voltage level of the
differential signal, while the low voltage level is determined by the current source of the HDMI
Source and the termination resistance at the Sink. The termination resistance (RT) and the
characteristic impedance of the cable (Z0) must be matched.
AVcc
RT
Transmitter
RT
Z0
D
D
Current
Source
Receiver
Figure 4-22 Conceptual Schematic for one TMDS differential pair
A single-ended differential signal, representing either the positive or negative terminal of a
differential pair, is illustrated in Figure 4-23. The nominal high-level voltage of the signal is AVcc
and the nominal low-level voltage of the signal is (AVcc - Vswing). Since the swing is differential on
the pair, the net signal on the pair has a swing twice that of the single-ended signal, or 2Vswing.
The differential signal, as shown in Figure 4-24, swings between positive Vswing and negative Vswing.
AVcc
Vswing
Figure 4-23 Single-ended Differential Signal
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+Vswing
-Vswing
Figure 4-24 Differential Signal
The signal test points for a TMDS link are shown in Figure 4-25. TP1 is used for testing of HDMI
Sources and Transmitter components. TP2 is used for testing of HDMI Sinks and Receiver
components. TP1 and TP2 together are also used for testing of cables. The TMDS link
intermediate test point for the Automotive relay connection is shown as TP5 in Figure 4-26.
TP1
TP2
Transition
Pattern
Pattern
Tx
Rx
Wire
Board
Board
Plug
Receptacle
Receptacle
Source Device
Cable Assembly
Sink Device
Figure 4-25 TMDS Link Test Points
TP1
Pattern
Tx
Board
Transition
Transition
Wire
Wire
CE Plug
Receptacle
CE Source Device
TP2
TP5
CE Relay Cable Assembly
for Automotive
CE Relay
Receptacle
Pattern
Plug
Automotive Relay
Cable Assembly
Rx
Board
Receptacle
Automotive Sink Device
Figure 4-26 TMDS Link Test Points for Automotive (Relay Connection)
4.2.2
TMDS System Operating Conditions
The required operating conditions of the TMDS pairs are specified in Table 4-22.
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Table 4-22 Required Operating Conditions for HDMI Interface (see Figure 4-22)
Item
Value
Termination Supply Voltage, AVcc
3.3 Volts 5%
Termination Resistance, RT
50 ohms 10%
4.2.3
TMDS Specification and Testing Overview
4.2.3.1
Jitter and Eye Measurements: Ideal Recovery Clock
All TMDS Clock and Data signal jitter specifications are specified relative to an Ideal Recovery
Clock defined below. The Data jitter is not specified numerically, but instead, an HDMI device or
cable shall adhere to the appropriate eye diagram(s) when the TMDS data signals are measured
using an Ideal Recovery Clock as a trigger source.
The TMDS Clock signal may contain low-frequency jitter components, which can be tracked by a
Sink’s clock recovery circuitry, and high-frequency components, which are not typically tracked.
The purpose of the Ideal Recovery Clock is to give an accurate representation of link performance
when used as a trigger for eye diagram and clock jitter specifications. The relationship of clock
jitter to data jitter is specified only indirectly by the eye mask.
For the purposes of jitter and eye diagram specification, the Ideal Recovery Clock is defined
relative to the TMDS clock signal. The Ideal Recovery Clock shall be equivalent to the signal that
would be derived by a perfect PLL (Ideal Clock Recovery Unit) with a jitter transfer function shown
in Equation 4-1, when the TMDS clock signal were input into that PLL. This jitter transfer function
has the behavior of a low pass filter with 20dB/decade roll-off and with a –3dB point of 4MHz.
For the purposes of compliance testing, a Clock Recovery Unit is used to generate a Recovered
Clock, which is meant to approximate the Ideal Recovery Clock. This Recovered Clock is used for
measurement of the jitter and eye diagram.
H(j) = 1 / ( 1 + j / )
Where = 2F, F = 4.0 MHz
Equation 4-1
4.2.3.2
Jitter Transfer Function of Ideal CRU for Ideal Recovery Clock Definition
Reference Cable Equalizer
The signal degradation introduced by typical passive cables increases with the frequency of the
signal and the length of the cable. In order to accommodate passive copper cables of
market-required lengths at the very high frequencies supported by HDMI, higher-speed HDMI
Sinks are expected to support some sort of cable equalization function which allows them to
recover data from such cables.
For lower-speed operation, the HDMI cable is specified with respect to the worst-case Source
output eye (cable input eye) and the Sink input eye. For higher-speed operation, the HDMI cable
specification also assumes application by the Sink of a cable equalization function approximating
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the performance implied by the Reference Cable Equalizer, which is a specified mathematical
model of cable equalization.
The HDMI Sink is required to successfully recover the data stream from any compliant Sink input
signal. At high frequencies, a compliant Sink input signal is any signal that, after application of the
Reference Cable Equalizer to each of the differential TMDS signals, results in a signal that meets
the Sink input eye requirements.
The definition of the Reference Cable Equalizer is given in Equation 4-2. The gain of this equation
is shown in Figure 4-27.
e A*
( 0 )
N
B*( 1.2*0 ) 2 C
H ( j ) e
e D* E
(0 1.4 * 0 )
(1.4 * 0 )
Where :
N 0.7
0 2 * 2.25GHz
A 7.34 E 8
7
B * A * 01.3
4
C 1.07 * A * 00.7
D 0.7 *A * 00.3
E 1.98 * A * 00.7
Equation 4-2
Reference Cable Equalizer Function
Gain
10.0
1.0
0.1
0
2
Frequency [GHz]
4
6
8
Figure 4-27 Gain of Reference Cable Equalizer
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e A*
2
H ( j ) e B*( 1.2* 0 ) C
e D* E
N
Version 1.4b
( 0 )
(0 1.4 * 0 )
(1.4 * 0 )
Where :
N 0.7
0 2 * 0.7425GHz
A 1.42 E 7
7
* A * 01.3
4
C 1.07 * A * 00.7
B
D 0.7 *A * 0 0.3
E 1.98 * A * 00.7
Equation 4-3
Reference Cable Equalizer Function for Automotive
Gain
10.0
1.0
0.1
0
2
Frequency [GHz]
4
6
8
Figure 4-28 Gain of Reference Cable Equalizer for Automotive
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4.2.4
Version 1.4b
HDMI Source TMDS Characteristics
HDMI requires a DC-coupled TMDS link. Source electrical testing shall be performed using the
test load shown in Figure 4-29, with AVcc set to 3.3V. TP1 represents the connection point of the
receptacle.
Figure 4-29 Balanced Source Test Load
The Source shall meet the DC specifications in Table 4-23 for all operating conditions specified in
Table 4-22 when driving clock and data signals. The Vswing parameter is the difference between
the single-ended most common high-level voltage (as would be revealed with a histogram
measurement) and the most-common low-level voltage, after ringing has subsided.
Note: According to the current drive concept of the TMDS link illustrated on Figure 4-22, Source
should not drive the TMDS line in a manner which exceeds the conditions defined in Table 4-23
even during Sink’s non-operating condition.
Table 4-23 Source DC Characteristics at TP1
Item
Value
Single-ended standby (off) output voltage, VOFF
AVcc 10mVolts
Single-ended output swing voltage, Vswing
400mVolts Vswing 600mVolts
Single-ended high level output voltage, VH
if attached Sink supports only <=165MHz :
AVcc 10mVolts
if attached Sink supports >165MHz :
(AVcc – 200mVolts) VH (AVcc + 10mVolts)
Single-ended low level output voltage, VL
if attached Sink supports only <=165MHz :
(AVcc – 600mVolts) VL (AVcc – 400mVolts)
if attached Sink supports >165MHz :
(AVcc – 700mVolts) VL (AVcc – 400mVolts)
It is recommended that Sources capable of higher speeds incorporate an effective amount of
source termination, especially if using Type C connectors. This termination will typically have the
effect of lowering the average DC level of each single-ended signal. The relaxed VH and VL
parameters permit such an implementation.
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The Source shall meet the AC specifications in Table 4-24 across all operating conditions
specified in Table 4-22. Rise and fall times are defined as the signal transition time between 20%
and 80% of the nominal swing voltage (Vswing) of the device under test.
The Source intra-pair skew is the maximum allowable time difference (on both low-to-high and
high-to-low transitions) as measured at TP1, between the true and complement signals of a given
differential pair. This time difference is measured at the midpoint on the single-ended signal swing
of the true and complement signals. The Source inter-pair skew is the maximum allowable time
difference (on both low-to-high and high-to-low transitions) as measured at TP1, between any two
single-ended data signals that do not constitute a differential pair.
Table 4-24 Source AC Characteristics at TP1
Item
Value
Rise time / fall time (20%-80%)
75psec Rise time / fall time
Intra-Pair Skew at Source Connector, max
0.15 Tbit
Inter-Pair Skew at Source Connector, max
0.20 Tcharacter
Clock duty cycle, min / average / max
40% / 50% / 60%
TMDS Differential Clock Jitter, max
0.25 Tbit (relative to Ideal Recovery Clock as
defined in Section 4.2.3)
The design of a Source should take into account the differential impedance of the cable assembly
and Sink of 100 ohms (see Table 4-29).
For all channels under all operating conditions specified in Table 4-22 and when terminated as
shown in Figure 4-29, the Source shall have output levels at TP1 that meet the eye diagram
requirements of Figure 4-30. This requirement specifies the minimum eye opening as well as the
absolute maximum and minimum voltages. The time axis is normalized to the bit time at the
operating frequency.
Absolute Differential Amplitude (mV)
The absolute amplitude limits in Figure 4-30 allow 25% (of the average differential swing voltage)
maximum undershoot when the differential signal has a minimum swing (800mV) and greater
undershoot for higher swings. Overshoot limits are imposed only by the absolute max/min
voltages of ±780mV shown above and below the normalized eye.
780
200
0
-200
-780
0.0
0.15
0.25
0.75
0.85
1.0
Normalized Time
Figure 4-30 Eye Diagram Mask at TP1 for Source Requirements
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Combining the single-ended swing voltage (Vswing) specified in Table 4-23 with a 15% overshoot
(legacy) and the undershoot limits of Table 4-24, it is possible to calculate the minimum and
maximum high-level voltage (Vhigh) and low-level voltage (Vlow) that is allowable on the interface.
Vhigh (max) = Vswing (max) + 15% (2Vswing (max) ) = 600 + 180 = 780 mV
Vhigh (min) = Vswing (min) - 25% (2Vswing (min) ) = 400 - 200 = 200 mV
Vlow (max) = -Vswing (max) - 15% (2Vswing (max) ) = -600 - 180 = -780 mV
Vlow (min) = -Vswing (min) + 25% (2Vswing (min) ) = -400 + 200 = -200 mV
Minimum opening at Source = Vhigh (min) - Vlow (min) = 400 mV
Note that the combination of these extreme cases do not constitute a single valid eye.
Source eye diagram test procedures are defined in the HDMI Compliance Test Specification.
4.2.5
HDMI Sink TMDS Characteristics
HDMI Sink electrical testing shall be performed using a test signal generator as shown in Figure
4-31.
TP2
AVcc
Test
Signal
Generator
or
Test
Fixture
Pattern
Termination Resistance RT
Rx
Board
Receptacle
Figure 4-31 HDMI Sink Test Points
There may be a risk of source damage if the Sink asserts a very high or very low voltage, such as
beyond the maximum ratings in the DVI 1.0 specification, on any TMDS line during power-on or
other power transitions.
The Sink shall meet the signal requirements listed in Table 4-25, Table 4-26, and Table 4-27.
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Table 4-25 Sink Operating DC Characteristics at TP2
Item
Value
Input Differential Voltage Level, Vidiff
150 Vidiff 1200 mVolts
Input Common Mode Voltage, Vicm
Vicm1
if Sink supports only <=165MHz :
(AVcc – 300mVolts) Vicm1 (AVcc – 37.5mVolts)
If Sink supports >165MHz :
(AVcc – 400mVolts) Vicm1 (AVcc – 37.5mVolts)
Vicm2
AVcc ±10mVolts
All Sinks are required to support both Vicm ranges (Vicm1 and Vicm2). Sources are not yet permitted
to operate in the Vicm2 (AC-coupled) range. At higher speeds, Source devices may implement
source termination, which may lower the DC-coupled Vicm (Vicm1) seen by the Sink.
Table 4-26 Sink DC Characteristics When Source Disabled or Disconnected at TP2
Item
Value
Differential Voltage Level
AVcc ±10mVolts
Table 4-27 Sink AC Input Characteristics at TP2
Item
Value
Minimum differential sensitivity (peak-to-peak)
150 mVolts
Maximum differential input (peak-to-peak)
1560 mVolts
Max Allowable Intra-Pair Skew at Sink Connector
For TMDS Clock rates 222.75MHz and below:
0.4 Tbit
For TMDS Clock rates above 222.75MHz:
0.15 Tbit + 112psecs
Max Allowable Inter-Pair Skew at Sink Connector
0.2 Tcharacter + 1.78nsecs
TMDS Clock Jitter
0.30 Tbit (relative to Ideal Recovery Clock as
defined in Section 4.2.3, and, for all TMDS clock
rates >165MHz: after application of Reference
Cable Equalizer given in Equation 4-2)
Note: According to the current drive concept of the TMDS link illustrated on Figure 4-22, Sink
should tolerate the situation when Source drives the TMDS line within the conditions defined in
Table 4-23 even in Sink’s non-operating condition.
For each channel under all operating conditions specified in this section the following conditions
shall be met.
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At TMDS clock frequencies less than or equal to 165MHz, the Sink shall recover data at a
TMDS character error rate of 10-9 or better, when presented with any signal compliant to the
eye diagram of Figure 4-32.
At TMDS clock frequencies above 165MHz, the Sink shall recover data on each channel at a
TMDS character error rate of 10-9 or better, when presented with any signal compliant to the
eye diagram of Figure 4-32 after application of the Reference Cable Equalizer.
For Automotive
For Automotive, the Sink shall recover data on each channel at a TMDS character error rate of
10-9 or better, when presented with any signal compliant to the eye diagram of Figure 4-32
after application of the Reference Cable Equalizer for Automotive.
Automotive cable parameters are specified only for Category 1 (up to 74.25MHz), so that the
Automotive applications can be operated up to 74.25MHz.
Absolute Differential Amplitude (mV)
780
75
0
-75
-780
0.0
0.25
0.35
0.65
0.75
1.0
Normalized Time
Figure 4-32 Eye Diagram Mask at TP2 for Sink Requirements
Table 4-28 HDMI Sink Impedance Characteristics at TP2
Item
Value
TDR Rise Time at TP2 (10%-90%)
200 psec
Through connection impedance
100 ohms 15% *
At Termination impedance
(when Vicm is within Vicm1 range)
100 ohms 10%
At Termination impedance
(when Vicm is within Vicm2 range)
100 ohms 35%
* A single excursion is permitted out to a max/min of 100 ohms 25% and of a duration less than 250psecs.
4.2.6
Cable Assembly TMDS Characteristics
The term “Cable assembly” includes all five parts listed below:
Source-side plug
Source-side transition (from plug to cable)
Cable itself
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Sink-side transition
Sink-side plug
Version 1.4b
Four types of cable assembly are defined based on the material of the cable itself:
Wire: Wire-only construction with no circuit components (neither active nor passive).
Passive: Wire plus passive circuit components. No active circuit components.
Active: Contains active circuit components with equalizer function. Does not have Tx or Rx
function.
Converter: Contains Rx and Tx functions. Any transmission media like wireless, optical fiber,
etc. may be used between the Rx and Tx functions. Acts as a 1to1 repeater where both ends
are cable plugs.
HDMI cable assemblies are measured with respect to the test points TP3 and TP4 shown in
Figure 4-33. TP1 and TP2 are not available because connection points between plug and
receptacle cannot be accessed during testing. Therefore, TP3 and TP4 are used, even though the
effects of receptacles at both ends are included in the test result. Similarly, TP6 is also used in
place of TP5 as shown in Figure 4-34 and Figure 4-35.
TP3
TP4
Cable Assembly
Transition
Wire
Receptacle
Receptacle
Plug
Figure 4-33 Cable Assembly Test Points
TP3
TP6
Automotive CE Relay Cable Assembly
Transition
Wire
Receptacle
Receptacle
Plug
Figure 4-34 Automotive CE Relay Cable Assembly Test Points (Relay Connection)
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TP6
TP4
Automotive Relay Cable Assembly
Transition
Wire
CE Plug
Receptacle
Receptacle
Plug
Figure 4-35 Automotive Relay Cable Assembly Test Points (Relay Connection)
HDMI cable assemblies shall support both Vicm ranges (Vicm1 and Vicm2) given in Table 4-25.
HDMI cable assemblies can fall into one of two categories: Category 1, supporting TMDS clock
frequencies up to 74.25MHz and Category 2, supporting TMDS clock frequencies up to 340MHz
HDMI cable assemblies are specified and tested using two different eye measurement
procedures: “non-equalized” (without application of the Reference Cable Equalizer) and
“equalized” (with application of the Reference Cable Equalizer).
Non-equalized eye diagram specification – when driven by any TMDS input waveform meeting
the Source eye diagram mask requirements of Figure 4-30 at the tested TMDS clock
frequency, the HDMI cable assembly shall produce a TMDS output waveform that meets the
Sink eye diagram mask of Figure 4-32.
Equalized eye diagram specification – when driven by any TMDS input waveform meeting the
Source eye diagram mask requirements of Figure 4-30 at the tested TMDS clock frequency,
the TMDS output waveform of the cable shall meet the post-equalized eye diagram mask of
Figure 4-32 after application of the Reference Cable Equalizer.
The application of these two different specifications depends upon the cables frequency rating:
Category 1 (up to 74.25MHz): The cable shall meet either:
A) the parameters specified for Category 1 cables in Table 4-29, or,
B) the non-equalized eye diagram requirements at 74.25MHz.
Category 2 (up to 340MHz): The cable shall meet either
A) the parameters specified for Category 2 cables in Table 4-29, or,
B) all of:
the non-equalized eye diagram requirements at 165MHz and,
the equalized eye diagram requirements at 340MHz
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Table 4-29 Cable Assembly TMDS Parameters
Parameter
Category 1 (up to
74.25MHz)
Category 2 (up to 340MHz)
Maximum Cable Assembly Intra-Pair Skew
151psec
112psec
Maximum Cable Assembly Inter-Pair Skew
2.42nsec
1.78nsec
Far-end Crosstalk
< -20dB
< -20dB
Attenuation
See Figure 4-36
See Figure 4-37
(note) For cables with passive
equalizer circuits, see the passive
cable descriptions below.
Differential Impedance
100 ohms 15% **
Connection point and transition area:
Up to 1nsec*
100 ohms 10%
Cable area: 1nsec – 2.5nsec *
* Measurement point for TDR measurement of impedance.
** A single excursion is permitted out to a max/min of 100 ohms 25% and of a duration less than 250psecs.
Cat.1 "Sufficient Condition" Attenuation
Frequency [MHz]
0
825
1650
2475
3300
4125
4950
0.0
5.0
8.0
10.0
15.0
20.0
21.0
25.0
30.0
dB
30.0
35.0
40.0
45.0
50.0
Figure 4-36 Category 1 Cable Attenuation Limits – Sufficient Condition
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Cat.2 "Sufficient Condition" 5dB Attenuation
Frequency [MHz]
0
825
1650
2475
3300
4125
4950
5775
0.0
5.0
10.0
5.0
12.0
15.0
20.0
20.0
25.0
25.0
30.0
dB
35.0
40.0
45.0
50.0
5100MHz
Figure 4-37 Category 2 Cable Attenuation Limits – Sufficient Condition
Passive Cables
Some HDMI cable assemblies include a passive equalizer circuit. In general, since the Passive
cable can also be extracted as a set of S-parameter, this type of cable can be specified using the
parametric values in the same manner as a normal copper cable. The only difference is a certain
additional requirements are specified for parameters as shown below.
Category 2 (TMDS clock up to 340MHz): Any passive equalizer circuit embedded in the cable
shall meet either
A) the parameters specified for Category 2 cables in Table 4-30 or,
B) all of:
the non-equalized eye diagram requirements at 165MHz and,
the equalized eye diagram requirements at 340MHz and,
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Table 4-30 Cable Assembly TMDS Parameters
Parameter
Category 1 (up to
74.25MHz)
Category 2 (up to
340MHz)
Maximum Cable Assembly Intra-Pair Skew
151psec
112psec
Maximum Cable Assembly Inter-Pair Skew
2.42nsec
1.78nsec
Far-end Crosstalk
< -20dB
Attenuation and phase
See Figure 4-38
Phase
See Figure 4-40
Differential Impedance
Connection point and transition area: Up to
1nsec *
100 ohms 15%**
100 ohms 10%
Cable area: 1nsec – 2.5nsec *
* Measurement point for TDR measurement of impedance.
** A single excursion is permitted out to a max/min of 100 ohms ±25% and of duration less than 250psecs.
125MHz
0 dB
x dB
5 dB
825MHz
2.475GHz
4.125GHz
A
B
10dB
C
15dB
20dB
25dB
30dB
Measured attenuation curve.
Figure 4-38 Passive equalizer Cable Attenuation Limits – Sufficient Condition
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In Figure 4-38, if measured attenuation and phase value cross the masked area, the cable DUT
fails the parametric test. Here, the parameter A, B, C is calculated as
for (0 < x <5)
A= 0, B=12, C=20
for (5 < x < 8)
A= 2.5(x -5) +0.5, B= 3.0(x -5)+12, C= 10/3(x -5)+20
< The parameter x is a measured attenuation value at frequency 825MHz.>
(note)
If x=5, then the equation above becomes identically equal to Figure 4-37 “Category 2 Cable
Attenuation Limits – Sufficient Condition”.
825MHz
2.475GHz
4.125GHz
540
360
Phase (-180 ~ 180 deg.)
180
0
-180
-360
Expanded Phase
-540
Figure 4-39 Passive equalizer Cable Phase measurement method (explanation)
125MHz
90
1.7 GHz
825MHz
2.475GHz
2.72 GHz
60
18
4.125GHz
28.8
30
0 [degree]
-18
-30
- 28.8
-60
-90
Figure 4-40 Passive equalize Cable Phase Limits – Sufficient Condition
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The phase characteristic is plotted as the difference between the linear expanded phase line and
the calculated linear approximated value by using “Ordinary Least Squares”.
In general, phase response is measured as a linear response shown in Figure 4-39. The phase
tolerance is defined as a difference value of measured linear expanded phase and calculated
approximated 1st order line.
The approximation model is “Ordinary Least Squares” of y=mx. (Here, “y” is the linear expanded
phase value, “x” is frequency corresponding, and “m” is an incline parameter to be calculated.
The frequency range used for calculation of “m” is from 300kHz to 1.7GHz).
Automotive Cable Assembly
Table 4-31 Automotive Cable Assembly TMDS Parameters (Direct Connection)
Parameter
Category 1 (up to 74.25MHz)
Maximum Cable Assembly Intra-Pair Skew
336psec
Maximum Cable Assembly Inter-Pair Skew
5.38nsec
Far-end Crosstalk
< -20dB
Attenuation
Eye Pattern with EQ for Automotive at TP2
Differential Impedance
Connection point and transition area: Up to 1nsec*
100 ohms 15% **
Cable area: 1nsec – 2.5nsec *
100 ohms 10%
* Measurement point for TDR measurement of impedance.
** A single excursion is permitted out to a max/min of 100 ohms 25% and of a duration less than 250psecs.
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Table 4-32 CE Relay Cable Assembly TMDS Parameters (Relay Connection)
Parameter
Category 1 (up to 74.25MHz)
Maximum Cable Assembly Intra-Pair Skew
101psec
Maximum Cable Assembly Inter-Pair Skew
1.61nsec
Far-end Crosstalk
< -20dB
Attenuation
Eye Pattern for Automotive at TP5
Differential Impedance
Connection point and transition area: Up to 1nsec*
100 ohms 15% **
Cable area: 1nsec – 2.5nsec *
100 ohms 10%
* Measurement point for TDR measurement of impedance.
Absolute Differential Amplitude (mV)
** A single excursion is permitted out to a max/min of 100 ohms 25% and of a duration less than 250psecs.
780
130
0
-130
-780
0.0
0.19
0.29
0.71
0.81
1.0
Normalized Time
Figure 4-41 Eye Diagram Mask at TP5 for CE Relay Cable
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Table 4-33 Automotive Relay Cable Assembly TMDS Parameters (Relay Connection)
Parameter
Category 1 (up to 74.25MHz)
Maximum Cable Assembly Intra-Pair Skew
235psec
Maximum Cable Assembly Inter-Pair Skew
3.77nsec
Far-end Crosstalk
< -20dB
Attenuation
Eye Pattern with EQ for Automotive at TP2
Differential Impedance
Connection point and transition area: Up to 1nsec*
100 ohms 15% **
Cable area: 1nsec – 2.5nsec *
100 ohms 10%
* Measurement point for TDR measurement of impedance.
** A single excursion is permitted out to a max/min of 100 ohms 25% and of a duration less than 250psecs.
4.2.7
+5V Power Signal
The HDMI connector provides a pin allowing the Source to supply +5.0 Volts to the cable and Sink.
All HDMI Sources shall assert the +5V Power signal whenever the Source is using the DDC or
TMDS signals. The voltage driven by the Source shall be within the limits specified for TP1 voltage
in Table 4-34. An HDMI Source shall have +5V Power signal over-current protection of no more
than 0.5A.
All HDMI Sources shall be able to supply a minimum of 55 mA to the +5V Power pin.
A Sink shall not draw more than 50 mA of current from the +5V Power pin. When the Sink is
powered on, it can draw no more than 10mA of current from the +5V Power signal. A Sink shall
assume that any voltage within the range specified for TP2 voltage in Table 4-34 indicates that a
Source is connected and applying power to the +5V Power signal.
A Cable Assembly shall be able to supply a minimum of 50mA to the +5V Power pin to a Sink,
even when connected to a Source supplying no more than 55mA.
The return for the +5V Power signal is DDC/CEC Ground signal.
Table 4-34 +5V Power Pin Voltage
Item
Min
Max
TP1 voltage
4.8 Volts
5.3 Volts
TP2 voltage
4.7 Volts
5.3 Volts
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DDC
The Display Data Channel (DDC) I/Os and wires (SDA, SCL, DDC/CEC Ground), shall meet the
requirements specified in the I2C-bus Specification, version 2.1, Section 15 for “Standard-Mode”
devices. Note that the discussions of high capacitance environments in the I2C-bus Specification,
section 17.2, “Switched pull-up circuit for Fast-mode I2C-bus”, may be applied to the HDMI
environment as well.
HDMI devices shall have DDC electrical characteristics complying with the values shown in Table
4-35, Table 4-36 and Table 4-37.
The exact method and measurement procedure is written in HDMI Compliance Test Specification.
In some cases, buffers or I2C “accelerators” may be inserted in the cable as long as all I2C timing
requirements are met.
Table 4-35 Maximum Capacitance of DDC line
Item
HDMI Source
Cable Assembly
HDMI Sink
SDA – DDC/CEC Ground
50pF
700pF
50pF
SCL – DDC/CEC Ground
50pF
700pF
50pF
Table 4-36 Maximum Capacitance of DDC line for Automotive
Item
HDMI
Source
Cable Assembly
HDMI Sink
Automotive
CE Relay
Automotive
Cable
Cable
Relay Cable
SDA – DDC/CEC Ground
50pF
700pF
210pF
490pF
50pF
SCL – DDC/CEC Ground
50pF
700pF
210pF
490pF
50pF
Table 4-37 Pull-up Resistance on DDC Lines
Item
Value
Source Pull-up resistors for SCL and SDA signals
minimum 1.5k ohms, maximum 2.0k ohms
Sink Pull-up resistors for SCL signal
47k ohms, 10%
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Hot Plug Detect Signal (HPD)
The ground reference for the Hot Plug Detect signal is the DDC/CEC Ground pin.
Table 4-38 Required Output Characteristics of Hot Plug Detect Signal
Item
Value
High voltage level (Sink)
Minimum 2.4 Volts, Maximum 5.3 Volts
Low voltage level (Sink)
Minimum 0 Volts, Maximum 0.4 Volts
Output resistance
1000 ohms 20%
Table 4-39 Required Detection Levels for Hot Plug Detect Signal
Item
Value
High voltage level (Source)
Minimum 2.0 Volts, Maximum 5.3 Volts
Low voltage level (Source)
Minimum 0 Volts, Maximum 0.8 Volts
Note that many Sink devices simply connect the HPD signal to the +5V Power signal through a
1000 ohm resistor. It may therefore be necessary for a Source to pull-down the HPD signal in
order to reliably differentiate between a floating (disconnected) HPD and a high voltage level HPD
signal.
4.2.10
CEC Line
The following line characteristics are required for all products, including those that do not
implement the CEC protocol. Further requirements for those devices that implement the CEC
protocol are given in Supplement 1. The ground reference for the CEC signal is the DDC/CEC
Ground signal.
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Table 4-40 CEC line Electrical Specifications for all Configurations
Item
Rule / Description
Line connectivity
Value
CEC lines from all HDMI inputs (if present) and a single HDMI output (if
present) shall be interconnected.
However, the following exceptions are allowed:
A device that has no HDMI output is allowed to have
separate CEC lines for each HDMI connector if that device implements
CEC protocol and takes a logical address of 0 on each CEC line. Due
to the complexity of handling multiple active CEC lines, this is
discouraged.
A device (typically a TV or media receiver box) that is acting
as the CEC root device shall not connect the CEC line to any HDMI
output.
Maximum resistance of such interconnected CEC line between any two
HDMI connectors:
Power-off
characteristics
CEC Line Capacitance
4.2.11
5
A device with power removed shall not degrade communication
between other CEC devices (e.g. the line shall not be pulled down by
the powered off device).
Maximum CEC line leakage current in off (unpowered) state
1.8µA
Maximum capacitance load of a Source, or of a Repeater that is not a
CEC root device
150pF
Maximum capacitance load of a Sink or of a CEC root device
200pF
Maximum capacitance load of a Cable Assembly
700pF
Maximum capacitance load of an Automotive Cable Assembly
700pF
Maximum capacitance load of a CE Relay Cable Assembly
210pF
Maximum capacitance load of an Automotive Relay Cable Assembly
490pF
Utility Line
This line may be used for multiple purposes (see HEAC as specified in Supplement 2). Its use is
controlled using the Capability Discovery and Control protocol specified in Supplement 2 and the
Consumer Electronics Control protocol specified in Supplement 1. The ground reference for the
Utility signal is the DDC/CEC Ground signal.
Table 4-41 Utility line Electrical Specifications (Recommendation)
Item
Impedance
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Robustness Requirements
No damage to the HDMI Source or Sink can result from the shorting of any combination of signals
on any connector. If two HDMI Sources are connected together with a single cable, no damage
can occur to either of the Sources. If two HDMI Sinks are connected together with a single cable,
no damage can occur to either of the Sinks.
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5
Signaling And Encoding
5.1
Overview
5.1.1
Link Architecture
As shown in Figure 5-1, an HDMI link includes three TMDS Data channels and a single TMDS
Clock channel. The TMDS Clock channel constantly runs at a rate proportional to the pixel rate of
the transmitted video. During every cycle of the TMDS Clock channel, each of the three TMDS
data channels transmits a 10-bit character. This 10-bit word is encoded using one of several
different coding techniques.
The input stream to the Source’s encoding logic will contain video pixel, packet and control data.
The packet data consists of audio and auxiliary data and associated error correction codes.
These data items are processed in a variety of ways and are presented to the TMDS encoder as
either 2 bits of control data, 4 bits of packet data or 8 bits of video data per TMDS channel. The
Source encodes one of these data types or encodes a Guard Band character on any given clock
cycle.
HDMI
TMDS Link
Input Streams
Output Strea ms
D[3:0]
Pixel component (e.g. G)
D[7:0]
CTL0, CTL1
D[1:0]
Auxiliary Data
(e.g. Audio Sample)
D[3:0]
Pixel component (e.g. R)
D[7:0]
CTL2, CTL3
D[1:0]
Auxiliary Data
(e.g. Audio Sample)
D[3:0]
Pixel Clock
Channel 1
Channel 2
Clock Channel
Recovery /
Decoder
Auxiliary Data
(e.g. Packet Header)
Channel 0
Recovery /
Decoder
D[1:0]
Sink
Recovery /
Decoder
H,VSYNC
Encoder /
Serializer
D[7:0]
Encoder /
Seriali zer
Pixel component (e.g. B)
Encoder /
S erializer
Source
D[7:0]
Pixel component (e.g. B)
D[1:0]
H,VSYNC
D[3:0]
Auxiliary Data
(e.g. Packet Header)
D[7:0]
Pixel component (e.g. G)
D[1:0]
CTL0, CTL1
D[3:0]
Auxiliary Data
(e.g. Audio Sample)
D[7:0]
Pixel component (e.g. R)
D[1:0]
CTL2, CTL3
D[3:0]
Auxiliary Data
(e.g. Audio Sample)
Pixel Clock
Figure 5-1 HDMI Encoder/Decoder Overview
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Operating Modes Overview
The HDMI link operates in one of three modes: Video Data Period, Data Island period, and Control
period. During the Video Data Period, the active pixels of an active video line are transmitted.
During the Data Island period, audio and auxiliary data are transmitted using a series of packets.
The Control period is used when no video, audio, or auxiliary data needs to be transmitted. A
Control Period is required between any two periods that are not Control Periods.
An example of each period placement is shown in the following figure.
Active Video
horizontal blanking
138 pixels
525 total lines
V
S
Y
N
C
480 act ive lines
45 lines
vertical blanking
HSYNC
720 active pixels
858 total pixels
Control Period
Data Island Period
TMDS Periods
Video Data Period
Figure 5-2 Informative Example: TMDS periods in 720x480p video frame
Video Data Periods use transition minimized coding to encode 8 bits per channel, or 24 bits total
per pixel.
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Data Island Periods are encoded using a similar transition minimized coding, TMDS Error
Reduction Coding (TERC4), which transmits 4 bits per channel, or 12 bits total per TMDS clock
period.
During Control Periods, 2 bits per channel, or 6 bits total are encoded per TMDS clock using a
transition maximized encoding. These 6 bits are HSYNC, VSYNC, CTL0, CTL1, CTL2 and CTL3.
Near the end of every Control Period, a Preamble, using the CTLx bits, indicates whether the next
Data Period is a Video Data Period or a Data Island Period.
Each Video Data Period and Data Island Period starts with a Leading Guard Band designed to
provide robust determination of the transition from the Control Period to the Data Period. This
Leading Guard Band consists of two special characters.
The Data Island Period is also protected by a Trailing Guard Band, which is designed to provide a
robust determination of the transition to Control Period.
The following table shows Encoding type used and data transmitted during each operating mode.
Table 5-1 Encoding Type and Data Transmitted
Period
Data Transmitted
Encoding Type
Video Data
Video Pixels
Video Data Coding
(8 bits converted to 10 bits)
(Guard Band)
(Fixed 10 bit pattern)
Packet Data
- Audio Samples
- InfoFrames
TERC4 Coding
(4 bits converted to 10 bits)
Data Island
HSYNC, VSYNC
Control
(Guard Band)
(Fixed 10 bit pattern)
Control
- Preamble
- HSYNC, VSYNC
Control Period Coding
(2 bits converted to 10 bits)
5.2
Operating Modes
5.2.1
Control Period
Control Period is used for transmission of the Preamble. The Control Period is also used by the
Sink for character synchronization.
The HDCP-specified Enhanced Encryption Status Signaling ENC_EN code (CTL0:3=1001) shall
not be used except as a correct ENC_EN during the HDCP-specified window of opportunity.
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Preamble
Immediately preceding each Video Data Period or Data Island Period is the Preamble. This is a
sequence of eight identical Control characters that indicate whether the upcoming data period is a
Video Data Period or is a Data Island. The values of CTL0, CTL1, CTL2, and CTL3 indicate the
type of data period that follows. The remaining Control signals, HSYNC and VSYNC, may vary
during this sequence.
There are only two legal Preamble characters:
Table 5-2 Preambles for Each Data Period Type
CTL0
CTL1
CTL2
CTL3
Data Period Type
1
0
0
0
Video Data Period
1
0
1
0
Data Island Period
The Video Data Period type indicates that the following data period contains video data, beginning
with a Video Guard Band.
The Data Island type indicates that the following data period is an HDMI compliant Data Island,
beginning with a Data Island Guard Band.
The transition from TMDS control characters to Guard Band characters following this sequence
identifies the start of the Data Period.
The Data Island Preamble control code (CTL0:3=1010) shall not be transmitted except for correct
use during a Preamble period.
5.2.1.2
Character Synchronization
The TMDS Sink needs to determine the location of character boundaries in the serial data streams.
Once character boundaries are established on all data channels, the Sink is defined to be
synchronized to the serial streams, and may recover TMDS characters from the data channels for
decode. The TMDS data stream provides periodic cues for decoder synchronization.
The TMDS characters used during the Video Data Period and Data Island Period contain five or
fewer transitions, while the TMDS characters used during the Control Period contain seven or
more transitions. The high-transition content of the characters transmitted during the Control
Period form the basis for character boundary synchronization at the decoder. While these
characters are not individually unique in the serial data stream, they are sufficiently alike that the
decoder may uniquely detect the presence of a succession of them during transmitted
synchronization intervals. The exact algorithm for this detection is an implementation detail
beyond the scope of this document, but minimum conditions for Sink synchronization are defined.
The Sink is required to establish synchronization with the data stream during any Control Period
greater than or equal to tS,min (12) characters in length.
The Source is also required to occasionally transmit an Extended Control Period per Table 5-4.
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Table 5-3 TMDS Link Timing Parameters
Parameter
Description
Value
Unit
tS,min
Minimum duration Control Period
12
TPIXEL
Table 5-4 Extended Control Period Parameters
Parameter
Description
Value
Unit
tEXTS,max_delay
Maximum time between Extended Control Periods
50
msec
tEXTS,min
Minimum duration Extended Control Period
32
TPIXEL
5.2.2
Video Data Period
Video data periods are used to carry the pixels of an active video line.
Each Video Data Period is preceded by a Preamble, described above.
Following the Preamble, the Video Data Period begins with a two character Video Leading Guard
Band. There is no Trailing Guard Band for the Video Data Period.
During active video periods, 24 bits of pixel data are encoded using TMDS transition minimized
encoding during each TMDS clock period.
5.2.2.1
Video Guard Band
Table 5-5 Video Leading Guard Band Values
case (TMDS Channel Number):
0: q_out[9:0] = 0b1011001100;
1: q_out[9:0] = 0b0100110011;
2: q_out[9:0] = 0b1011001100;
endcase
5.2.3
Data Island Period
5.2.3.1
Data Island Overview
Data Islands are used to carry packets of audio sample data and auxiliary data. This auxiliary data
includes InfoFrames and other data describing the active audio or video stream or describing the
Source.
Each Data Island is preceded by a Preamble, described above.
Following the Preamble, each Island starts with a Leading Guard Band. The first packet of the
Data Island then follows.
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During every TMDS clock period of the Data Island, including the Guard Band, bits 0 and 1 of
TMDS Channel 0 transmit an encoded form of HSYNC and VSYNC.
Bit 2 of TMDS Channel 0 is used to transmit the Packet Header. All four bits of TMDS Channels 1
and 2 are used for the Packet data as shown in Figure 5-3. Each packet is 32 pixels long and is
protected by BCH ECC for error correction and detection purposes.
During the Data Island, each of the three TMDS channels transmits a series of 10-bit characters
encoded from a 4-bit input word, using TMDS Error Reduction Coding (TERC4). TERC4
significantly reduces the error rate on the link by choosing only 10-bit codes with high inherent
error avoidance.
The last two characters of the Data Island, following the last packet, is the Trailing Guard Band.
Period CTL Peri od
Data Isla nd Peri od
Encoding CTL Encodi ng G B
CTL Perio d
TERC4 Encod ing (HDCP e ncryp ted )
GB
Vi deo Data Pe rio d
CTL E ncodi ng
GB
HSYNC
VSYNC
Vid eo
En co din g
HSYNC
VSYN C
1
1
Packet Header 1
0
Packet H eader 2.. .
1
1
1
Le ading G uard Ba nd
HSYNC
VSYNC
Active vid eo
pi xe ls...
Le adi ng Guard Ban d
D0
D1
D2
D3
D4
D5
D6
D7
Active vid eo
pi xe ls...
Leadi ng Gu ard Ban d
TMDS Channel 0
Active vid eo
pi xe ls...
1
P reambl e
P acke t 1
Pa cket 2...
T railin g G uar d B and
D0
D1
D2
D3
D4
D5
D6
D7
Le adi ng Guard Ban d
TMDS Channel 1
P reambl e
TMDS
Clocks: >=4
P reambl e
8
2
P acke t 1
Pa cket 2...
32
32
Trail in g G ua rd B and
D0
D1
D2
D3
D4
D5
D6
D7
Leadi ng Gu ard Ban d
TMDS Channel 2
2
P reambl e
>=4
8
2
Figure 5-3 TMDS Periods and Encoding
Following the Data Island, all three channels revert to transmitting control characters.
5.2.3.2
Island Placement and Duration
The Source is required to determine the temporal placement and duration of the Data Island with
respect to the video signal’s horizontal and vertical blanking periods and synchronization signals.
It shall do so following the rules stated below.
All TMDS Control Periods shall be at least tS,min (12) characters (pixels) long.
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The Data Island shall contain at least one packet, limiting its minimum size to 36 pixels.
Islands shall contain an integer number of packets. In order to assure the reliability of the data
within the Data Island, they shall be limited to 18 packets or fewer.
Zero, one or more Data Islands can occur between subsequent video data periods.
While transmitting video, at least one Data Island shall be transmitted during every two video
fields.
5.2.3.3
Data Island Guard Bands
The first two data characters within the Data Island are the Leading Guard Band. The last two data
characters within the Data Island are the Trailing Guard Band.
During the Data Island Guard Bands, Channel 0 is encoded as one of four TERC4 values. These
TERC4 values (D[3:0]) are 0xC, 0xD, 0xE and 0xF, depending upon the values of HSYNC and
VSYNC.
Table 5-6 Data Island Leading and Trailing Guard Band Values
case (TMDS Channel Number):
0: q_out[9:0] = n.a.;
1: q_out[9:0] = 0b0100110011;
2: q_out[9:0] = 0b0100110011;
endcase
5.2.3.4
Data Island Packet Construction
All data within a Data Island is contained within 32 clock Packets. Packets consist of a Packet
Header, a Packet Body (consisting of four Subpackets), and associated error correction bits. Each
Subpacket includes 56 bits of data and is protected by an additional 8 bits of BCH ECC parity bits.
Subpacket 0 plus its corresponding parity bits make up BCH Block 0. This block is mapped onto
bit 0 of both Channel 1 and Channel 2. In this way, the 64 bits of BCH Block 0 are transferred over
the course of 32 pixels. Likewise, BCH Block 1 (Subpacket 1 plus parity) is mapped onto bit 1 of
both Channels 1 and 2.
In the tables below, Header bytes are indicated as HB0, HB1, and HB2 and Subpacket bytes are
indicated as SB0 to SB6.
Subpacket 0 bytes 0 through 6 (SB0-SB6) are also designated Packet bytes 0 to 6 (PB0-PB6).
Subpacket 1 bytes 0 through 6 (SB0-SB6) are also designated Packet bytes 7 to 13 (PB7-PB13).
Subpacket 2 bytes 0 through 6 (SB0-SB6) are also designated Packet bytes 14 to 20
(PB14-PB20).
Subpacket 3 bytes 0 through 6 (SB0-SB6) are also designated Packet bytes 21 to 27
(PB21-PB27).
This is illustrated in Figure 5-4.
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Char0 Char1 Char2
Char 31
Channel 0
0A0
0A1
0A2
0A3
1A0
1A1
1A2
1A3
2A0
2A1
2A2
2A3
31A0
31A1
31A2
31A3
0B0
0B1
0B2
0B3
1B0
1B1
1B2
1B3
2B0
2B1
2B2
2B3
31B0
31B1
31B2
31B3
0C0
0C1
0C2
0C3
1C0
1C1
1C2
1C3
2C0
2C1
2C2
2C3
31C0
31C1
31C2
31C3
0B0
0C0
1B0
1C0
2B0
2C0
3B0
3C0
31B0
31C0
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
bit 6
bit 7
D0
D1
D2
D3
HSYNC
VSYNC
BCH block 4
x
Channel 1
D0
D1
D2
D3
BCH block 0
BCH block 1
BCH block 2
BCH block 3
Channel 2
D0
D1
D2
D3
BCH block 0
Byte 0
Packet Body
Subpacket 0
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
parity bits
BCH block 0
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
parity bits
BCH block 1
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
parity bits
BCH block 2
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
parity bits
BCH block 3
Subpacket 3
0A2
1A2
2A2
3A2
4A2
5A2
6A2
7A2
30A2
31A2
BCH block 4
Packet Header
Byte 0
Byte 1
Byte 2
parity bits
Figure 5-4 Data Island Packet and ECC Structure
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High-Definition Multimedia Interface Specification
5.2.3.5
Version 1.4b
Data Island Error Correction
To improve the reliability of the data and to improve the detection of bad data, Error Correction
Code (ECC) parity is added to each packet. BCH(64,56) and BCH(32,24) are generated by the
polynomial G(x) shown in Figure 5-5.
G(x)=1+x6+x7+x8 (127 count repetition cycle).
/T (Synd rome)
Synd rome
x6
x7
+
x8
+
+
Data In pu t
Figure 5-5 Error Correction Code generator
5.3
Data Island Packet Definitions
5.3.1
Packet Header
Packet Headers contain 24 data bits with an additional 8 bits of BCH(32,24) ECC parity. These
parity bits are calculated over the 24 bits of the Packet Header.
A Packet Header includes an 8-bit Packet Type and 16 bits of packet-specific data.
A Sink shall be able to receive, with no adverse effects, any packet defined in the HDMI 1.0
specification including any InfoFrame Packet with an InfoFrame Type defined in CEA-861-D.
Table 5-7 Packet Header
Byte \ Bit #
7
6
5
4
3
HB0
Packet Type
HB1
packet-specific data
HB2
packet-specific data
2
1
0
Table 5-8 shows the available packet types.
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Table 5-8 Packet Types
Packet Type Value
Packet Type
Described in
Section
0x00
Null
5.3.2
0x01
Audio Clock Regeneration (N/CTS)
5.3.3
0x02
Audio Sample (L-PCM and IEC 61937 compressed formats)
5.3.4
0x03
General Control
5.3.6
0x04
ACP Packet
5.3.7
0x05
ISRC1 Packet
5.3.8
0x06
ISRC2 Packet
“
0x07
One Bit Audio Sample Packet
5.3.9
0x08
DST Audio Packet
5.3.10
0x09
High Bitrate (HBR) Audio Stream Packet (IEC 61937)
5.3.11
0x0A
Gamut Metadata Packet
5.3.12
0x80+InfoFrame
Type
InfoFrame Packet
5.3.5
0x81
Vendor-Specific InfoFrame
8.2.3
0x82
AVI InfoFrame*
8.2.1
0x83
Source Product Descriptor InfoFrame
--
0x84
Audio InfoFrame*
8.2.2
0x85
MPEG Source InfoFrame
--
* See Section 8.2 for the packet layout for these InfoFrames
5.3.2
Null Packet
Null packets can be used by the Source anytime. All bytes of a Null packet are undefined and shall
contain only zero values. An HDMI Sink shall ignore bytes HB1 and HB2 of the Null Packet
Header and all bytes of the Null Packet Body.
Table 5-9 Null Packet Header
Byte \ Bit #
7
6
5
4
3
2
1
0
HB0
0
0
0
0
0
0
0
0
HB1
0
0
0
0
0
0
0
0
HB2
0
0
0
0
0
0
0
0
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High-Definition Multimedia Interface Specification
5.3.3
Version 1.4b
Audio Clock Regeneration Packet
Audio Clock Regeneration Packets contain both the N and CTS values used in the Audio Clock
Regeneration process. The four Subpackets each contain the same Audio Clock Regeneration
Subpacket. An HDMI Sink shall ignore bytes HB1 and HB2 of the Audio Clock Regeneration
Packet header.
Table 5-10 Audio Clock Regeneration Packet Header
Byte \ Bit #
7
6
5
4
3
2
1
0
HB0
0
0
0
0
0
0
0
1
HB1
0
0
0
0
0
0
0
0
HB2
0
0
0
0
0
0
0
0
Table 5-11 Audio Clock Regeneration Subpacket
Byte \ Bit #
7
6
5
4
3
2
1
0
SB0
0
0
0
0
0
0
0
0
SB1
0
0
0
0
CTS.19
-
-
CTS.16
SB2
CTS.15
-
-
-
-
-
-
CTS.8
SB3
CTS.7
-
-
-
-
-
-
CTS.0
SB4
0
0
0
0
N.19
-
-
N.16
SB5
N.15
-
-
-
-
-
-
N.8
SB6
N.7
-
-
-
-
-
-
N.0
N
[20 bits] value of audio clock regeneration “N”
CTS
[20 bits] Cycle Time Stamp
CTS values of zero are used to indicate no new value of CTS.
5.3.4
Audio Sample Packet
L-PCM and some IEC 61937 compressed audio formats are carried using Audio Sample Packets.
Audio Sample Packets consist of one to four Audio Samples. These may be different samples or
different partial samples (i.e. 2 of 6 channels). The configuration of the Subpackets is determined
by the layout and sample_present bits in the header. This is described in detail in Section 7.6,
Audio Data Packetization.
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Table 5-12 Audio Sample Packet Header
Byte \ Bit #
7
6
5
4
3
2
1
0
HB0
0
0
0
0
0
0
1
0
HB1
0
0
0
layout
sample_
present.sp3
sample_
present.sp2
sample_
present.sp1
sample_
present.sp0
HB2
B.3
B.2
B.1
B.0
sample_flat
.sp3
sample_flat
.sp2
sample_flat
.sp1
sample_flat
.sp0
layout:
[1 bit] indicates which of two possible Subpacket/audio sample layouts are
used. See Section 7.6, Audio Data Packetization.
sample_present.spX [4 fields, 1 bit each] indicates if Subpacket X contains audio sample(s).
sample_flat.spX
[4 fields, 1 bit each] indicates if Subpacket X represents a “flatline”
sample. Only valid if “sample_present.spX” is set.
B.X
[4 fields, 1 bit each] B.X =1 if Subpacket X contains the first frame in a 192
frame IEC 60958 Channel Status block; B.X = 0 otherwise
Table 5-13 Audio Sample Subpacket
Byte \ Bit #
7
6
5
4
3
2
1
0
SB0
L.11
-
-
-
-
-
-
L.4
SB1
L.19
-
-
-
-
-
-
L.12
SB2
L.27
-
-
-
-
-
-
L.20
SB3
R.11
-
-
-
-
-
-
R.4
SB4
R.19
-
-
-
-
-
-
R.12
SB5
R.27
-
-
-
-
-
-
R.20
SB6
PR
CR
UR
VR
PL
CL
UL
VL
L.X:
[24 fields, 1 bit each] Bit corresponding to Time Slot X from first (“left”)
sub-frame per IEC 60958-1, page 15
R.X:
[24 fields, 1 bit each] Bit corresponding to Time Slot X from second (“right”)
sub-frame per IEC 60958-1, page 15
VL:
[1 bit] Valid bit from first sub-frame
VR:
[1 bit] Valid bit from second sub-frame
UL:
[1 bit] User Data bit from first sub-frame
U R:
[1 bit] User Data bit from second sub-frame
CL:
[1 bit] Channel Status bit from first sub-frame
C R:
[1 bit] Channel Status bit from second sub-frame
PL:
[1 bit] Parity bit from first sub-frame (even parity)
PR:
[1 bit] Parity bit from second sub-frame (even parity)
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High-Definition Multimedia Interface Specification
5.3.5
Version 1.4b
InfoFrame Packet
All InfoFrames defined in CEA-861-D may be carried across HDMI using the HDMI InfoFrame
packet. InfoFrames not defined in CEA-861-D or in this specification shall not be transmitted.
Each HDMI InfoFrame Packet carries a single CEA InfoFrame, as shown below 1 . Note that HDMI
places additional requirements on several InfoFrames that are not covered by CEA-861-D. For
these additional details and restrictions, see Section 8.2.
Table 5-14 InfoFrame Packet Header
Byte \ Bit #
7
HB0
1
6
5
4
3
2
1
0
InfoFrame Type
HB1
InfoFrame_version
HB2
0
0
0
InfoFrame_length
InfoFrame Type
CEA-861-D.
[7 bits] least significant 7 bits of the InfoFrame type code as per
InfoFrame_version
[1 byte] version number of InfoFrame as per CEA-861-D.
InfoFrame_length
[5 bits] InfoFrame length in bytes as per CEA-861-D. This length does
not include any of the bytes in the Packet Header nor the checksum byte. The maximum value
for this field is 27 (0x1B).
Table 5-15 InfoFrame Packet Contents
Byte \ Bit #
7
6
5
4
3
PB0
Checksum
PB1
Data Byte 1
PB2
Data Byte 2
PB3...PB26
-
PB27
Data Byte 27
2
1
0
Checksum
[1 byte] Checksum of the InfoFrame. The checksum shall be calculated such
that a byte-wide sum of all three bytes of the Packet Header and all valid bytes of the
InfoFrame Packet contents (determined by InfoFrame_length), plus the checksum itself,
equals zero.
Data Byte X [27 fields, 1 byte each] Data Byte X of the InfoFrame as defined in CEA-861-D.
See [HDMI Specification] Section 8.2 for more information.
1
An earlier version of CEA-861-D, CEA-861B, had a method for encapsulating multiple CEA
InfoFrames into a single CEA InfoPacket. HDMI has its own packet structure and therefore CEA
InfoPackets are not used.
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High-Definition Multimedia Interface Specification
5.3.6
Version 1.4b
General Control Packet
The General Control packet header contains no data. Bytes HB1 and HB2 shall be ignored by the
Sink. The General Control packet body shall contain four identical subpackets, defined in Table
5-17, below.
Table 5-16 General Control Packet Header
Byte \ Bit #
7
6
5
4
3
2
1
0
HB0
0
0
0
0
0
0
1
1
HB1
0
0
0
0
0
0
0
0
HB2
0
0
0
0
0
0
0
0
Table 5-17 General Control Subpacket
Byte \ Bit #
7
6
5
4
3
2
1
0
SB0
0
0
0
Clear_AVMUTE
0
0
0
Set_AVMUTE
SB1
PP3
PP2
PP1
PP0
CD3
CD2
CD1
CD0
SB2
0
0
0
0
0
0
0
Default_Phase
SB3
0
0
0
0
0
0
0
0
SB4
0
0
0
0
0
0
0
0
SB5
0
0
0
0
0
0
0
0
SB6
0
0
0
0
0
0
0
0
Set_AVMUTE
[1 bit] Set the AVMUTE flag. (See description below).
Clear_AVMUTE
[1bit] Clear the AVMUTE flag. (See description below).
PP
[4 bits] Pixel Packing Phase. (See description in section 6.5.3.)
CD
[4 bits] Color Depth. (See description in section 6.5.3.)
Default_Phase
[1 bit] Default Phase. (See description in section 6.5.3.)
The General Control Packet contains fields for indicating AVMUTE information and color-depth
information. Each transmitted GCP may contain valid indications for AVMUTE and/or color-depth
or may contain no information (all fields zero).
General Control packets indicating Set_AVMUTE or Clear_AVMUTE may only be transmitted
between the active edge of VSYNC and 384 pixels following this edge. A Source may not send a
General Control Packet with the Clear_AVMUTE and Set_AVMUTE flags set simultaneously.
Source transmission of the General Control Packet is optional. Sinks may optionally interpret
General Control Packet contents. Sinks shall be capable of receiving any General Control Packet.
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The General Control packet’s Set_AVMUTE and Clear_AVMUTE flags may be used by a Source
to reduce the negative impact on the Sink of TMDS clock changes or interruptions. Use of the
AVMUTE function may prevent spurious pops or noises in the audio during these clock changes.
When AVMUTE is set, the Sink may assume that no valid audio or video data is being received.
The Sink may optionally apply a mute function to the audio data and/or a blank function to the
video.
5.3.7
Audio Content Protection Packet (ACP)
A Source may use the ACP Packet to convey content-related information regarding the active
audio stream.
See Section 9.3 for rules regarding the use of the ACP packet.
The following tables show the packetization of the ACP Packet.
Table 5-18 ACP Packet Header
Byte \ Bit #
7
6
5
4
3
HB0
Packet Type = 0x04
HB1
ACP_Type
HB2
Reserved (0)
2
1
0
ACP_Type
[1 byte] Content protection type (see Section 9.3 for usage):
0x00
= Generic Audio
0x01
= IEC 60958-Identified Audio
0x02
= DVD-Audio
0x03
= Super Audio CD
0x04...0xFF
Reserved
Table 5-19 ACP Packet contents
Packet
Byte #
7
6
PB0-PB27
ACP_Type_Dependent
See Section 9.3 for usage.
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4
3
2
1
0
ACP_Type_Dependent
(Dependent upon ACP_Type value)
[28 bytes] Contents are dependent upon ACP_Type field.
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High-Definition Multimedia Interface Specification
5.3.8
Version 1.4b
ISRC Packets
A Source may use the ISRC packets to transmit a UPC/EAN or ISRC code. See Section 8.8 for
rules regarding the use of the ISRC packets.
Table 5-20 ISRC1 Packet Header
Byte \ Bit #
7
6
HB0
HB1
5
4
3
2
1
0
Packet Type = 0x05
ISRC_
Cont
HB2
ISRC_
Valid
Reserved (0)
ISRC_Status
Reserved (0)
ISRC_Cont
[1 bit] ISRC Continued (in next packet). See Section 8.8 for usage.
ISRC_Status
[3 bits] See Section 8.8 for usage.
ISRC Valid
[1 bit]: This bit is set only when data located in ISRC_Status field and
UPC_EAN_ISRC_X field are valid. When Source cannot obtain complete data for these
fields, ISRC_Valid may be 0.
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Table 5-21 ISRC1 Packet contents
Packet Byte #
7
6
5
4
3
PB0
UPC_EAN_ISRC_0
PB1
UPC_EAN_ISRC_1
PB2
UPC_EAN_ISRC_2
PB3
UPC_EAN_ISRC_3
PB4
UPC_EAN_ISRC_4
PB5
UPC_EAN_ISRC_5
PB6
UPC_EAN_ISRC_6
PB7
UPC_EAN_ISRC_7
PB8
UPC_EAN_ISRC_8
PB9
UPC_EAN_ISRC_9
PB10
UPC_EAN_ISRC_10
PB11
UPC_EAN_ISRC_11
PB12
UPC_EAN_ISRC_12
PB13
UPC_EAN_ISRC_13
PB14
UPC_EAN_ISRC_14
PB15
UPC_EAN_ISRC_15
PB16-PB27
Reserved (0)
2
1
0
UPC_EAN_ISRC_X [16 fields, 1 byte each] UPC/EAN or ISRC byte X. See Section 8.8
for usage.
Bytes PB16-PB27 shall be set to a value of 0.
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Table 5-22 ISRC2 Packet Header
Byte \ Bit #
7
6
5
4
3
HB0
Packet Type = 0x06
HB1
Reserved (0)
HB2
Reserved (0)
2
1
0
Table 5-23 ISRC2 Packet contents
Packet
Byte #
7
6
5
4
3
PB0
UPC_EAN_ISRC_16
PB1
UPC_EAN_ISRC_17
PB2
UPC_EAN_ISRC_18
PB3
UPC_EAN_ISRC_19
PB4
UPC_EAN_ISRC_20
PB5
UPC_EAN_ISRC_21
PB6
UPC_EAN_ISRC_22
PB7
UPC_EAN_ISRC_23
PB8
UPC_EAN_ISRC_24
PB9
UPC_EAN_ISRC_25
PB10
UPC_EAN_ISRC_26
PB11
UPC_EAN_ISRC_27
PB12
UPC_EAN_ISRC_28
PB13
UPC_EAN_ISRC_29
PB14
UPC_EAN_ISRC_30
PB15
UPC_EAN_ISRC_31
PB16-PB27
Reserved (0)
2
1
0
UPC_EAN_ISRC_X [16 fields, 1 byte each] UPC/EAN or ISRC byte X.
Bytes PB16-PB27 shall be set to a value of 0.
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High-Definition Multimedia Interface Specification
5.3.9
Version 1.4b
One Bit Audio Sample Packet
One Bit Audio streams are transmitted using the One Bit Audio Sample Packet.
One Bit Audio Packets consist of one to four One Bit Audio Subpackets. These may be different
samples or different partial samples (e.g. 2 of 6 channels). The configuration of the Subpackets is
determined by the layout and samples_present bits in the header. This is described in detail in
Section 7.6, Audio Data Packetization.
It is optional for the Source, Sink and Repeater to support the One Bit Audio packet.
Table 5-24 One Bit Audio Packet Header
Byte \ Bit #
7
6
5
4
3
2
1
0
HB0
0
0
0
0
0
1
1
1
HB1
Rsvd
(0)
Rsvd
(0)
Rsvd
(0)
layout
samples_
present.sp3
samples_
present.sp2
samples_
present.sp1
samples_
present.sp0
HB2
Rsvd
(0)
Rsvd
(0)
Rsvd
(0)
Rsvd
(0)
samples_
invalid.sp3
samples_
invalid.sp2
samples_
invalid.sp1
samples_
invalid.sp0
layout
[1 bit] indicates which of two possible Subpacket/audio sample
layouts are used. See Table 5-25 below and Section 7.6, Audio Data
Packetization.
samples_present.spX
[4 fields, 1 bit each] indicates if Subpacket X contains audio sample
data. Samples_present.spX = 1 if subpacket X contains sample data;
else = 0.
samples_invalid.spX
[4 fields, 1 bit each] indicates if Subpacket X represents invalid
samples. Samples_invalid = 1 if the samples in Subpacket X are
invalid; else = 0. This bit is only valid if the relevant
“samples_present.spX” is set.
Note that, for One Bit Audio, sample frequency information is carried in the Audio InfoFrame (see
section 8.2.2).
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Table 5-25 One Bit Audio Subpacket
Byte \ Bit #
7
6
5
4
3
2
1
0
SB0
ChA.7
-
-
-
-
-
-
ChA.0
SB1
ChA.15
-
-
-
-
-
-
ChA.8
SB2
ChA.23
-
-
-
-
-
-
ChA.16
SB3
ChB.7
-
-
-
-
-
-
ChB.0
SB4
ChB.15
-
-
-
-
-
-
ChB.8
SB5
ChB.23
-
-
-
-
-
-
ChB.16
SB6
ChB.27
ChB.26
ChB.25
ChB.24
ChA.27
ChA.26
ChA.25
ChA.24
ChA.X:
[28 fields, 1 bit each] indicates consecutive One Bit Audio samples of the first
channel. The most significant bit (ChA.27) is the first sampled bit of the consecutive 28-bit
part in the One Bit Audio stream.
ChB.X:
[28 fields, 1 bit each] indicates consecutive One Bit Audio samples of the
second channel. The most significant bit (ChB.27) is the first sampled bit of the
consecutive 28-bit part in the One Bit Audio stream.
5.3.10
DST Audio Packet
DST (compressed DSD) audio streams are transmitted using the DST Audio Packet.
A DST Audio Packet contains a single DST Audio Packet Body which is filled as audio data
becomes available. All identification of channels and other data is embedded in the stream. DST
Audio Packet packing is described further in 7.6.3, DST Packetization.
It is optional for a Source, Sink or Repeater to support the DST Audio Packet.
Table 5-26 DST Audio Packet Header
Byte \ Bit #
7
6
5
4
3
2
1
0
HB0
0
0
0
0
1
0
0
0
HB1
frame_
start
samples_
invalid
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
DST_normal
_double
HB2
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
frame_start
[1 bit] =1 indicates that this packet is the start of a DST frame; =0
otherwise.
samples_invalid
[1 bit] = 1 if the samples are not valid; = 0 if the samples are valid.
DST_Normal_Double
[1 bit] =0 (“DST_Normal”) indicates that the sample rate equals the
transfer rate. =1 (“DST_Double”) indicates that the transfer rate is
twice the sample rate. DST_Double rate is used when normal does
not have sufficient bandwidth.
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Note that, for DST, sample frequency information is carried in the Audio InfoFrame (see section
8.2.2).
Each DST Audio Packet Body contains 224 bits (28 bytes) of DST data. DST stream data is taken
in byte order and packed into the DST Audio Packet Body as shown in Table 5-27.
Table 5-27 DST Audio Packet Body
Byte \ Bit #
7
6
5
4
3
2
1
0
PB0
D.7
D.6
D.5
D.4
D.3
D.2
D.1
D.0
PB1
D.15
D.14
D.13
D.12
D.11
D.10
D.9
D.8
-
-
-
-
-
-
-
-
-
PB26
D.215
D.214
D.213
D.212
D.211
D.210
D.209
D.208
PB27
D.223
D.222
D.221
D.220
D.219
D.218
D.217
D.216
D.X
5.3.11
[224 fields, 1 bit each] DST bitstream, beginning with D.0.
High-Bitrate (HBR) Audio Stream Packet
High bitrate (>6.144Mbps) compressed audio streams conforming to IEC 61937 are carried using
HBR Audio Stream Packets. Each packet carries four contiguous IEC 60958 frames which
corresponds to (4x2x16 =) 128 contiguous bits of an IEC 61937 stream. This is described in more
detail in Section 7.6.2, High-Bitrate Audio Stream Packetization.
Table 5-28 HBR Audio Stream Packet Header
Byte \ Bit #
7
6
5
4
3
2
1
0
HB0
0
0
0
0
1
0
0
1
HB1
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
HB2
B.3
B.2
B.1
B.0
Rsvd (0)
Rsvd (0)
Rsvd (0)
Rsvd (0)
B.X
[4 fields, 1 bit each] B.X =1 if Subpacket X contains the first frame in a 192
frame IEC 60958 Channel Status block; B.X = 0 otherwise
The HBR Audio Stream Packet uses four subpackets which are identical to the Audio Sample
Subpacket shown above in Table 5-13.
5.3.12
Gamut Metadata Packet
Gamut boundary descriptions (GBD) and other gamut-related metadata are carried using the
Gamut Metadata Packet. Gamut metadata is further described in Appendix E.
One of several transmission profiles (P0, P1, P2, etc.) can be used when sending GBDs using this
packet. The difference between the transmission profiles is primarily the transmission rate,
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specifically, the number of packets that may be sent per video field. The transmission profile is
indicated in the field GBD_profile.
The lowest transmission profile (P0) also has a specific size limitation; it fits within a single Gamut
Metadata Packet. Higher transmission profiles (P1, P2, etc.) can be larger, requiring many packets
and possibly ten or more video fields for complete transmission.
Table 5-29 Gamut Boundary Description Metadata Profiles
Transmission
Profile Name
P0
P1
P2
P3
EDID Colorimetry
Data Block bit
MD0
MD1
MD2
MD3 *
Packets per Video Field
Total Packet Count
1
1
2-10
11-80
1
2-10
11-100
101-800
* This bit will be defined in a future specification.
Gamut metadata may be transmitted that describes the gamut of the currently transmitted video or
that of upcoming video. Each time the gamut of the video stream changes in a way that requires
transmission of new gamut metadata, a gamut sequence number is incremented. All metatdata
packets include two fields, Affected_Gamut_Seq_Num and Current_Gamut_Seq_Num, that
together indicate whether the metadata regards the current or the subsequent video stream. All
Gamut Metadata Packets within a single video field (VSYNC active edge to VSYNC active edge)
shall have the same Current_Gamut_Seq_Num field.
If a packet contains metadata for the currently transmitted video, Affected_Gamut_Seq_Num will
be equal to Current_Gamut_Seq_Num. If the packet regards upcoming video, the
Affected_Gamut_Seq_Num will be Current_Gamut_Seq_Num + 1 (mod 16). The field
Affected_Gamut_Seq_Num shall never be beyond Current_Gamut_Seq_Num + 1, therefore,
only current and next gamut may be described.
If it is known by the Source that a packet contains metadata that will be effective for the next video
field then the Next_Field flag shall be set, whether or not the metadata is effective for the current
video field.
Gamut metadata associated with upcoming video may be transmitted even when the current video
has no associated metadata. In this situation, all Gamut Metadata packets transmitted shall
indicate that the current stream has no associated metadata (i.e. colorimetry and gamut are
described by the currently-valid AVI InfoFrame) by setting No_Current_GBD to 1. At least one
such Gamut Metadata packet shall be transmitted in the VBLANK period. All Gamut Metadata
packets within that same video field can carry metadata for the upcoming video.
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GBD more than 2
fields before video
GBD more than 1
field before video
Actual
Video
GBD Info
at Source
G#4
G#4
GBD#4
G#4
G#5
GBD#5
G#5
G#5
G#6
GBD#6
VSYNC
Gamut
Metadata
packet
Current
=
G#4
Current
=
G#4
Current
=
G#4
Current
=
G#5
Current
=
G#5
Current
=
G#5
Current
=
G#6
Nxt_Fld=1
Nxt_Fld=1
Nxt_Fld=1
Nxt_Fld=1
Nxt_Fld=0
Nxt_Fld=1
Nxt_Fld=1
Affected
=
G#4
Affected
=
G#4
Affected
=
G#5
Affected
=
G#5
Affected
=
G#6
Affected
=
G#6
Affected
=
G#6
GBD
G#4
GBD
G#4
GBD
G#5
GBD
G#5
GBD
G#6
GBD
G#6
GBD
G#6
Sink’s
Conversion
table
G#4
G#5
G#6
Figure 5-6 Example P0 Transmission Sequence
During the transmission of any video stream that is accompanied by or requires gamut metadata,
at least one Gamut Metadata Packet containing a P0 transmission profile GBD shall be
transmitted during each VBLANK. This transmission shall occur before the end of the first
(VBLANK) video line following the active edge of VSYNC. If no Gamut Metadata Packet is
transmitted during this period, then the colorimetry and gamut of the subsequent VACTIVE for that
video field shall correspond to that described by the transmitted AVI InfoFrame.
If the Sink indicates support for P2 or higher transmission profiles then the Source may
simultaneously transmit two GBDs. In this case, within each video field, the Source may transmit:
a P0 profile containing the GBD for the current video and a portion of a higher profile containing
the GBD for either the current or the upcoming video. Alternatively, the two simultaneous GBDs
may be a P0 profile describing the current video and a P0 profile describing the upcoming video.
Table 5-30 Gamut Metadata Packet Header
Byte \ Bit #
7
6
5
4
3
2
1
0
HB0
0
0
0
0
1
0
1
0
HB1
Next_Field
HB2
No_Crnt
_GBD
GBD_profile
Rsvd (0)
Packet_Seq
Affected_Gamut_Seq_Num
Current_Gamut_Seq_Num
Next_Field[1 bit] Set to indicate that the GBD carried in this packet will be effective on the
next video field. Specifically, the Affected_Gamut_Seq_Num for this packet will be equal
to the Current_Gamut_Seq_Num for the next field. Next_Field should be set even if the
GBD is already effective (e.g. Current=Affected).
No_Current_GBD [1 bit] Set to indicate that there is no gamut metadata available for the
currently transmitted video (i.e. current video has a standard colorimetry not requiring a
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GBD). When set, the field Current_Gamut_Seq_Num is meaningless and shall be ignored
by the Sink.
GBD_profile
[3 bits] Transmission profile number:
0: P0
1: P1
2: P2
3: P3
other values: reserved.
Affected_Gamut_Seq_Num
metadata.
Current_Gamut_Seq_Num [4 bits] Indicates the gamut number of the currently
transmitted video stream. All Gamut Metadata Packets transmitted within the same video
field shall have the same Current_Gamut_Seq_Num, even if the
Affected_Gamut_Seq_Num varies among the packets.
Packet_Seq
[2 bits] Indicates whether this packet is the only, the first, an
intermediate or the last packet in a Gamut Metadata packet sequence.
= 0 (0b00) Intermediate packet in sequence
= 1 (0b01) First packet in sequence
= 2 (0b10) Last packet in sequence
= 3 (0b11) Only packet in sequence (i.e. P0)
[4 bits] Indicates which video fields are relevant for this
The Gamut Metadata Packet Body differs depending upon transmission profile and whether the
packet is the first of a sequence or one of the remaining packets in that sequence.
The packet body for a P0 transmission is defined in Table 5-31.
Table 5-31 Gamut Metadata Packet for P0 Transmission Profile
Packet
Byte #
7
PB00-PB27
6
5
4
3
2
1
0
GBD bytes 0 through 27
When transmitting any GBD requiring more than one Gamut Metadata Packet for transmission, a
packet containing the packet body shown in Table 5-32 shall be used. Subsequent packets in that
sequence shall use the packet body shown in Table 5-33. If the GBD ends midway through a
packet, the rest of the body shall be filled with zeroes by the Source and shall be ignored by the
Sink.
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Table 5-32 Gamut Metadata Packet for P1 and Higher – 1st Packet of Sequence
Packet
Byte #
7
6
5
4
3
PB0
GBD_Length_H
PB1
GBD_Length_L
PB2
Checksum
PB3-PB27
GBD bytes 0 through 24
2
1
0
GBD_Length(_H, _L)
[2 bytes] Total length (in bytes) of gamut metadata,
not including GBD_Length or Checksum.
Checksum [1 byte] Checksum of every byte covered by GBD_Length field.
Table 5-33 Gamut Metadata Packet for P1 and Higher – Remaining Packets
Packet
Byte #
7
6
5
PB00-PB27
5.4
Encoding
5.4.1
Serialization
4
3
2
1
0
Next 28 bytes of GBD
The stream of TMDS characters produced by the encoder is serialized for transmission on the
TMDS data channel. In the discussions that follow, the least significant bit of each character
(q_out[0]) is the first bit to be transmitted and the most significant bit (q_out[9]) is the last.
5.4.2
Control Period Coding
Each TMDS channel has two control signals, which are encoded into 10 bits during Control
Periods. For each of the three channels these signals are shown in Table 5-34.
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Table 5-34 Control-signal Assignment
TMDS Channel
D0
D1
0
HSYNC
VSYNC
1
CTL0
CTL1
2
CTL2
CTL3
The two Control signals for each of the three TMDS channels are encoded as follows:
case (D1, D0):
0, 0: q_out[9:0] = 0b1101010100;
0, 1: q_out[9:0] = 0b0010101011;
1, 0: q_out[9:0] = 0b0101010100;
1, 1: q_out[9:0] = 0b1010101011;
endcase;
5.4.3
TERC4 Coding
TMDS Error Reduction Coding (TERC4) is used during the Data Island period to encode 4 bits per
channel into the 10 bits serialized and transmitted.
case (D3, D2, D1, D0):
0000:
q_out[9:0] = 0b1010011100;
0001:
q_out[9:0] = 0b1001100011;
0010:
q_out[9:0] = 0b1011100100;
0011:
q_out[9:0] = 0b1011100010;
0100:
q_out[9:0] = 0b0101110001;
0101:
q_out[9:0] = 0b0100011110;
0110:
q_out[9:0] = 0b0110001110;
0111:
q_out[9:0] = 0b0100111100;
1000:
q_out[9:0] = 0b1011001100;
1001:
q_out[9:0] = 0b0100111001;
1010:
q_out[9:0] = 0b0110011100;
1011:
q_out[9:0] = 0b1011000110;
1100:
q_out[9:0] = 0b1010001110;
1101:
q_out[9:0] = 0b1001110001;
1110:
q_out[9:0] = 0b0101100011;
1111:
q_out[9:0] = 0b1011000011;
endcase;
5.4.4
Video Data Coding
5.4.4.1
Video Data Encoding
The following is a description of the encoding algorithm used during transmission of video data. A
detailed description of an encoder is given. Other implementations are possible and are permitted
but, given the same sequence of input characters, they are required to produce the same
sequence of output (10-bit) characters that is generated by the described encoder.
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During video data, where each 10-bit character represents 8 bits of pixel data, the encoded
characters provide an approximate DC balance as well as a reduction in the number of transitions
in the data stream. The encode process for the active data period can be viewed in two stages.
The first stage produces a transition-minimized 9-bit code word from the input 8 bits. The second
stage produces a 10-bit code word, the finished TMDS character, which will manage the overall
DC balance of the transmitted stream of characters.
The 9-bit code word produced by the first stage of the encoder is made up of an 8-bit
representation of the transitions found in the input 8 bits, plus a one-bit flag to indicate which of two
methods was used to describe the transitions. In both cases, the LSb of the output matches the
LSb of the input. With a starting value established, the remaining 7 bits of the output word is
derived from sequential exclusive OR (XOR) or exclusive NOR (XNOR) functions of each bit of the
input with the previously derived bit. The choice between XOR and XNOR logic is made such that
the encoded values contain the fewest possible transitions, and the ninth bit of the code word is
used to indicate whether XOR or XNOR functions were used to derive the output code word. The
decode of this 9-bit code word is simply a matter of applying either XOR or XNOR gates to the
adjacent bits of the code, with the LSb passing from decoder input to decoder output unchanged.
The second stage of the encoder performs an approximate DC balance on the transmitted stream
by selectively inverting the 8 data bits of the 9-bit code words produced by the first stage. A tenth
bit is added to the code word, to indicate when the inversion has been made. The encoder
determines when to invert the next character based on the running disparity between ones and
zeros that it tracks in the transmitted stream, and the number of ones and zeros found in the
current code word. If too many ones have been transmitted and the input contains more ones than
zeros, the code word is inverted. This dynamic encoding decision at the Source is simply decoded
at the Sink by the conditional inversion of the input code word based on the tenth bit of the TMDS
character. The TMDS code mapping is specified by Figure 5-7 with the definitions of Table 5-35.
The encoder produces one of 460 unique 10-bit characters. The encoder shall not generate any
other 10-bit character during a Video Data Period.
Upon entering a Video Data Period, the data stream disparity (cnt) shall be considered to be zero
by the encoder.
Table 5-35 Encoding Algorithm Definitions
D
The encoder input data set. D is 8-bit pixel data
cnt
This is a register used to keep track of the data stream disparity. A positive value
represents the excess number of “1”s that have been transmitted. A negative value
represents the excess number of “0”s that have been transmitted. The expression
cnt{t-1} indicates the previous value of the disparity for the previous set of input data.
The expression cnt(t) indicates the new disparity setting for the current set of input
data.
q_m
Intermediate value.
q_out
These 10 bits are the encoded output value.
N1{x}
This operator returns the number of “1”s in argument “x”
N0{x}
This operator returns the number of “0”s in argument “x”
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D[0:7], cnt(t-1)
FALSE
(N1{D}>4) OR
(N1{D} == 4 AND D[0] == 0)
q_m[0] = D[0];
q_m[1] = q_m[0] XNOR D[1];
q_m[2] = q_m[1] XNOR D[2];
...
...
...
q_m[7] = q_m[6] XNOR D[7];
q_m[8] = 0;
q_m[0] = D[0];
q_m[1] = q_m[0] XOR D[1];
q_m[2] = q_m[1] XOR D[2];
...
...
...
q_m[7] = q_m[6] XOR D[7];
q_m[8] = 1;
(Cnt(t-1)==0) OR
(N1{q_m[0:7]}==N0{q_m[0:7]})
FALSE
TRUE
TRUE
q_out[9]=~q_m[8];
q_out[8]=q_m[8];
q_out[0:7]=(q_m[8]) ? q_m[0:7]:~q_m[0:7]);
q_m[8]==0
(cnt(t-1)>0 AND
(N1{q_m[0:7]}>N0{q_m[0:7]})
OR
(cnt(t-1)<0 AND
N0{q_m[0:7]}>N1{q_m[0:7]})
TRUE
TRUE
FALSE
cnt(t) = cnt(t-1)+
(N1{q_m[0:7]} - N0{q_m[0:7]});
cnt(t) = cnt(t-1) +
(N0{q_m[0:7]} - N1{q_m[0:7]});
FALSE
q_out[9]=0;
q_out[8]=q_m[8];
q_out[0:7]=q_m[0:7];
Cnt(t)=Cnt(t-1) - 2*(~q_m[8]) +
(N1{q_m[0:7]} - N0{q_m[0:7]});
q_out[9]=1;
q_out[8]=q_m[8];
q_out[0:7]=~q_m[0:7];
Cnt(t) = Cnt(t-1) + 2*q_m[8] +
(N0{q_m[0:7]} - N1{q_m[0:7]});
Figure 5-7 TMDS Video Data Encode Algorithm
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5.4.4.2
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Video Data Decoding
The TMDS decode mapping is specified by Figure 5-8. Alternative implementations are possible
but, given the same input data stream, they are required to generate the same output data stream
as the described decoder algorithm.
D[9:0]
D[9] == 1
TRUE
D[7:0] := ~D[7:0];
FALSE
D[8] == 1
T RUE
FALSE
Q[0]
Q[1]
Q[2]
Q[3]
Q[4]
Q[5]
Q[6]
Q[7]
:= D[0];
:= D[1] XNOR
:= D[2] XNOR
:= D[3] XNOR
:= D[4] XNOR
:= D[5] XNOR
:= D[6] XNOR
:= D[7] XNOR
D[0];
D[1];
D[2];
D[3];
D[4];
D[5];
D[6];
Q[0] := D[0];
Q[1] := D[1] XOR D[0];
Q[2] := D[2] XOR D[1];
Q[3] := D[3] XOR D[2];
Q[4] := D[4] XOR D[3];
Q[5] := D[5] XOR D[4];
Q[6] := D[6] XOR D[5];
Q[7] := D[7] XOR D[6];
Figure 5-8 TMDS Video Decode Algorithm
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6
Video
6.1
Overview
Version 1.4b
HDMI allows any video format timing to be transmitted and displayed. To maximize interoperability
between products, common DTV formats have been defined. These video format timings define
the pixel and line counts and timing, synchronization pulse position and duration, and whether the
format is interlaced or progressive. HDMI also allows vendor-specific formats to be used.
The video pixels carried across the link shall be in one of three different pixel encodings: RGB
4:4:4, YCBCR 4:4:4 or YCBCR 4:2:2.
The HDMI Source determines the pixel encoding and video format of the transmitted signal based
on the characteristics of the source video, the format and pixel encoding conversions possible at
the Source, and the format and pixel encoding capabilities and preferences of the Sink.
6.2
Video Format Support
In order to provide maximum compatibility between video Sources and Sinks, specific minimum
requirements have been specified for Sources and Sinks.
6.2.1
Format Support Requirements
Some of the following support requirements are in addition to those specified in CEA-861-D.
An HDMI Source shall support at least one of the following video format timings:
640x480p @ 59.94/60Hz
720x480p @ 59.94/60Hz
720x576p @ 50Hz
An HDMI Source that is capable of transmitting any of the following video format timings using
any other component analog or uncompressed digital video output, shall be capable of
transmitting that video format timing across the HDMI interface.
1280x720p @ 59.94/60Hz
1920x1080i @ 59.94/60Hz
720x480p @ 59.94/60Hz
1280x720p @ 50Hz
1920x1080i @ 50Hz
720x576p @ 50Hz
An HDMI Sink that accepts 60Hz video formats shall support the 640x480p @ 59.94/60Hz and
720x480p @ 59.94/60Hz video format timings.
An HDMI Sink that accepts 50Hz video formats shall support the 640x480p @ 59.94/60Hz and
720x576p @ 50Hz video format timings.
An HDMI Sink that accepts 60Hz video formats, and that supports HDTV capability, shall
support 1280x720p @ 59.94/60Hz or 1920x1080i @ 59.94/60Hz video format timings.
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An HDMI Sink that accepts 50Hz video formats, and that supports HDTV capability, shall
support 1280x720p @ 50Hz or 1920x1080i @ 50Hz video format timings.
An HDMI Sink that is capable of receiving any of the following video format timings using any
other component analog or uncompressed digital video input, shall be capable of receiving
that format across the HDMI interface.
1280x720p @ 59.94/60Hz
1920x1080i @ 59.94/60Hz
1280x720p @ 50Hz
1920x1080i @ 50Hz
Additional recommendations for video format handling by Sources and Sinks are given in
Appendix F.
6.2.2
Video Control Signals : HSYNC, VSYNC
During the Data Island period, HDMI carries HSYNC and VSYNC signals using encoded bits on
Channel 0. During Video Data periods, HDMI does not carry HSYNC and VSYNC and the Sink
should assume that these signals remain constant. During Control periods, HDMI carries HSYNC
and VSYNC signals through the use of four different control characters on TMDS Channel 0.
6.2.3
Pixel Encoding Requirements
Only pixel encodings of RGB 4:4:4, YCBCR 4:2:2, and YCBCR 4:4:4 (as specified in Section 6.5)
may be used on HDMI.
All HDMI Sources and Sinks shall be capable of supporting RGB 4:4:4 pixel encoding.
All HDMI Sources shall support either YCBCR 4:2:2 or YCBCR 4:4:4 pixel encoding whenever that
device is capable of transmitting a color-difference color space across any other component
analog or digital video interface except where that device would be required to convert RGB video
to YCBCR in order to meet this requirement.
All HDMI Sinks shall be capable of supporting both YCBCR 4:4:4 and YCBCR 4:2:2 pixel encoding
when that device is capable of supporting a color-difference color space from any other
component analog or digital video input.
If an HDMI Sink supports either YCBCR 4:2:2 or YCBCR 4:4:4 then both shall be supported.
An HDMI Source may determine the pixel-encodings that are supported by the Sink through the
use of the E-EDID. If the Sink indicates that it supports YCBCR-formatted video data and if the
Source can deliver YCBCR data, then it can enable the transfer of this data across the link.
6.2.4
Color Depth Requirements
HDMI Sources and Sinks may support color depths of 24, 30, 36 and/or 48 bits per pixel. All HDMI
Sources and Sinks shall support 24 bits per pixel.
Color depths greater than 24 bits per pixel are defined to be “Deep Color” and several Deep Color
capability modes are defined in this Specification. All Deep Color modes are optional though if an
HDMI Source or Sink supports any Deep Color mode, it shall support 36-bit mode.
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For each supported Deep Color mode, RGB 4:4:4 shall be supported and optionally YCBCR 4:4:4
may be supported.
YCBCR 4:2:2 is also 36-bit mode but does not require the further use of the Deep Color modes
described in section 6.5.2 and 6.5.3.
An HDMI Sink shall support all EDID-indicated Deep Color modes on all EDID-indicated video
formats except if that combination exceeds the Max_TMDS_Clock indication.
An HDMI Source shall not send any Deep Color mode to a Sink that does not indicate support for
that mode.
6.3
Video Format Timing Specifications
All specified video line pixel counts and video field line counts (both active and total) and HSYNC
and VSYNC positions, polarities, and durations shall be adhered to when transmitting a specified
video format timing.
For example, if a Source is processing material with fewer active pixels per line than required (i.e.
704 pixels vs. 720 pixels for standard definition MPEG2 material), it may add pixels to the left and
right of the supplied material before transmitting across HDMI. AVI bar info may need to be
adjusted to account for these added pixels.
Detailed timing is found in CEA-861-D or a later version of CEA-861 for the following video format
timings.
6.3.1
Primary Video Format Timings
640x480p @ 59.94/60Hz
1280x720p @ 59.94/60Hz
1920x1080i @ 59.94/60Hz
720x480p @ 59.94/60Hz
720(1440)x480i @ 59.94/60Hz
1280x720p @ 50Hz
1920x1080i @ 50Hz
720x576p @ 50Hz
720(1440)x576i @ 50Hz
6.3.2
Secondary Video Format Timings
720(1440)x240p @ 59.94/60Hz
2880x480i @ 59.94/60Hz
2880x240p @ 59.94/60Hz
1440x480p @ 59.94/60Hz
1920x1080p @ 59.94/60Hz
720(1440)x288p @ 50Hz
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2880x576i @ 50Hz
2880x288p @ 50Hz
1440x576p @ 50Hz
1920x1080p @ 50Hz
1920x1080p @ 23.98/24Hz
1920x1080p @ 25Hz
1920x1080p @ 29.97/30Hz
2880x480p @ 59.94/60Hz
2880x576p @ 50Hz
1920x1080i (1250 total) @ 50Hz
720(1440)x480i @ 119.88/120Hz
720x480p @ 119.88/120Hz
1920x1080i @ 119.88/120Hz
1280x720p @ 119.88/120Hz
720(1440)x480i @ 239.76/240Hz
720x480p @ 239.76/240Hz
720(1440)x576i @ 100Hz
720x576p @ 100Hz
1920x1080i @ 100Hz
1280x720p @ 100Hz
720(1440)x576i @ 200Hz
720x576p @ 200Hz
1280x720p @ 23.98/24Hz
1280x720p @ 25Hz
1280x720p @ 29.97/30Hz
1920x1080p @ 119.88/120Hz
1920x1080p @ 100Hz
6.4
Version 1.4b
Pixel-Repetition
Video formats with native pixel rates below 25 Mpixels/sec require pixel-repetition in order to be
carried across a TMDS link. 720x480i and 720x576i video format timings shall always be
pixel-repeated.
The HDMI Source indicates the use of pixel-repetition with the Pixel Repetition (PR0:PR3) field in
the AVI InfoFrame. This field indicates to the HDMI Sink how many repetitions of each unique pixel
are transmitted. In non-repeated formats, this value is zero.
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For pixel-repeated formats, this value indicates the number of pixels that may be discarded by the
Sink without losing real image content.
The Source shall always accurately indicate the pixel repetition count being used. The use of the
Pixel Repetition field is optional for HDMI Sink.
The use of this pixel-repetition count field is more fully described in CEA-861-D.
6.5
Pixel Encodings and Color Depth
There are three different pixel encodings that may be sent across an HDMI cable: YCBCR 4:4:4,
YCBCR 4:2:2 and RGB 4:4:4. Whichever encoding is used, it shall conform to one of the methods
described in this section.
6.5.1
Pixel Encodings
Figure 6-1 shows the default encoding, RGB 4:4:4 for 24-bit color depth. The R, G, and B
components of the first pixel for a given line of video are transferred on the first pixel of the video
data period following the Guard Band characters.
Pixel 0
Pixel 1
Pixel 2
Pixel 3
Pixel 4
…
0
B0
B1
B2
B3
B4
…
1
G0
G1
G2
G3
G4
…
2
R0
R1
R2
R3
R4
…
TMDS
Channel
Figure 6-1 Default pixel encoding: RGB 4:4:4, 8 bits/component
Figure 6-2 shows the signal mapping and timing for transferring YCBCR 4:2:2 data across HDMI.
Because 4:2:2 data only requires two components per pixel, more bits are allocated per
component. The available 24 bits are split into 12 bits for the Y component and 12 bits for the C
components.
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Y0 / CB0
Y1 / CR0
Y2 / CB2
Y3 / CR2
Y4 / CB4
…
Bits 3-0
Y0 bits 3-0
Y1 bits 3-0
Y2 bits 3-0
Y3 bits 3-0
Y4 bits 3-0
…
Bits 7-4
CB0 bits 3-0
CR0 bits 3-0
CB2 bits 3-0
CR2 bits 3-0
CB4 bits 3-0
…
1
Bits 7-0
Y0 bits 11-4
Y1 bits 11-4
Y2 bits 11-4
Y3 bits 11-4
Y4 bits 11-4
…
2
Bits 7-0
CB0 bits 11-4
CR0 bits 11-4
CB2 bits 11-4
CR2 bits 11-4
CB4 bits 11-4
…
TMDS
Channel
0
Figure 6-2 YCBCR 4:2:2 component
The YCBCR 4:2:2 pixel encoding on HDMI closely resembles standard ITU-R BT.601. The
high-order 8 bits of the Y samples are mapped onto the 8 bits of Channel 1 and the low-order 4
bits are mapped onto the low-order 4 bits of Channel 0. If fewer than 12 bits are used, the valid bits
shall be left-justified (i.e. MSb=MSb) with zeroes padding the bits below the LSb.
The first pixel transmitted within a Video Data Period contains three components, Y0, Cb0 and Cr0.
The Y0 and Cb0 components are transmitted during the first pixel period while Cr0 is transmitted
during the second pixel period. This second pixel period also contains the only component for the
second pixel – Y1. In this way, the link carries one CB sample for every two pixels and one Cr
sample for every two pixels. These two components (CB and CR) are multiplexed onto the same
signal paths on the link.
At the third pixel, this process is repeated with the Y and CB components for the third pixel being
transmitted, followed, in the next pixel period, by the CR component of the third pixel and the Y
component of the fourth pixel.
YCBCR 4:4:4 data is transferred using the scheme illustrated in Figure 6-3.
Pixel 0
Pixel 1
Pixel 2
Pixel 3
Pixel 4
…
0
CB0
CB1
CB2
C B3
C B4
…
1
Y0
Y1
Y2
Y3
Y4
…
2
CR0
CR1
CR2
CR3
CR4
…
TMDS
Channel
Figure 6-3 8-bit YCBCR 4:4:4 mapping
6.5.2
Deep Color Pixel Packing
There are four Color Pixel Packing modes supported: 24-, 30-, 36- and 48-bits per pixel, defined
for RGB 4:4:4 and for YCBCR 4:4:4.
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For a color depth of 24 bits/pixel, pixels are carried at a rate of one pixel per TMDS clock. At
deeper color depths, the TMDS clock is run faster than the source pixel clock providing the extra
bandwidth for the additional bits. The TMDS clock rate is increased by the ratio of the pixel size to
24 bits:
24 bit mode: TMDS clock = 1.0 x pixel clock (1:1)
30 bit mode: TMDS clock = 1.25 x pixel clock (5:4)
36 bit mode: TMDS clock = 1.5 x pixel clock (3:2)
48 bit mode: TMDS clock = 2.0 x pixel clock (2:1)
When operating in a Deep Color mode, all video data (pixels) and signaling (HSYNC, VSYNC, DE
transitions) are grouped into a series of packed Pixel Groups, each carrying the same number of
pixels and each requiring the same number of TMDS clocks for transmission. On each TMDS
clock, one Fragment of the Pixel Group is transmitted. The number of pixels per group and number
of fragments per group depends on the pixel size:
24 bit mode: 1 pixel/group, 1 fragment/group
30 bit mode: 4 pixels/group, 5 fragments/group
36 bit mode: 2 pixels/group, 3 fragments/group
48 bit mode: 1 pixel/group, 2 fragments/group
During active video, the input pixel data is packed into these groups. During blanking, HSYNC and
VSYNC are packed into these same groups. In this way, all video-related protocol elements are
carried at a direct ratio to the pixel clock, thus ensuring no change to the relationship between the
pixel clock and the pixel data, DE transitions and HSYNC or VSYNC transitions. This also allows
any sequence of HSYNC, VSYNC, DE transitions, etc. that can be supported at 24 bits/pixel to be
supported equally in any other pixel size.
All other HDMI protocol elements are unaffected by the Deep Color pixel packing. Data Islands,
Video Guard Bands and Preambles occur as they do in normal (24-bit) mode – each Preamble is 8
TMDS clocks, each Data Island packet is 32 TMDS clocks, and each Guard Band is 2 TMDS
clocks.
As shown above, a pixel group consists of 1, 2, or 4 pixels. Each pixel group is broken into 1, 2, 3
or 5 pixel fragments transmitted one fragment per TMDS clock.
Each TMDS character period (one TMDS clock) in the transmitted stream carries a single
Fragment of a Pixel Group and so represents a particular Packing Phase of the group. It is
necessary for the Sink to determine which character in the stream of characters represents the
start of a new group, or phase 0, in order to synchronize its pixel unpacking state with the source’s
pixel packing state. To accomplish this, the source sends a packet indicating the packing phase of
a specific pixel (see 6.5.3 for packet details). This packet is sent at least once per video field
indicating the then-current packing phase. The sink uses this data to initially determine where
each new group starts should also use this periodic update to verify that it is still synchronized or to
recover from gross errors on the link.
The following tables specify all Pixel Encodings for all color depths. For each mode, the packing
for each phase is described. Packing phases for active video are identified as “mPn” (10P0, 10P1,
etc. while the packing phases for blanking are identified as “mCn” (10C0, 10C1, etc.).
24 bit mode: P (pixels/group) = 1 pixel; L (fragments/group) = 1 fragment (1 TMDS character).
Standard HDMI format.
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Fragment
Phase
Pixels
8P0
0
A
Version 1.4b
8 bit HDMI pixel data code (to encoder)
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
A0
A1
A2
A3
A4
Bit 5
A5
Bit 6
A6
Bit 7
A7
30 bit mode: P = 4 pixels; L = 5 fragments
8 bit HDMI pixel data code (to encoder)
Fragment
Phase Pixels
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
10P0
0
A
A0
A1
A2
A3
A4
10P1
1
A+B
A8
A9
B0
B1
B2
10P2
2
B+C
B6
B7
B8
B9
C0
10P3
3
C+D
C4
C5
C6
C7
C8
10P4
4
D
D2
D3
D4
D5
D6
Bit 5
A5
B3
C1
C9
D7
Bit 6
A6
B4
C2
D0
D8
Bit 7
A7
B5
C3
D1
D9
36 bit mode: P = 2 pixels; L = 3 fragments
8 bit HDMI pixel data code (to encoder)
Fragment Phase Pixels
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
12P0
0
A
A0
A1
A2
A3
A4
12P1
1
A+B
A8
A9
A10
A11
B0
12P2
2
B
B4
B5
B6
B7
B8
Bit 5
A5
B1
B9
Bit 6
A6
B2
B10
Bit 7
A7
B3
B11
Bit 6
A6
A14
Bit 7
A7
A15
48 bit mode: P = 1 pixel; L = 2 fragments
Fragment Phase Pixels
8 bit HDMI pixel data code (to encoder)
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
16P0
0
A
A0
A1
A2
A3
A4
16P1
1
A
A8
A9
A10
A11
A12
Bit 5
A5
A13
During blanking, one HSYNC and VSYNC value per pixel clock is carried in each Pixel Group.
This provides one more HSYNC and VSYNC slot per group than is required (e.g. 5 TMDS clocks
for 4 pixels) so the HSYNC and VSYNC values are simply repeated on the last TMDS clock of a
group.
The following tables specify, for each mode, the group size and the sequence of HSYNC and
VSYNC transmission within a group.
Source HSYNC/VSYNC values for each pixel are labeled S, T, U, V (as needed). Source
HSYNC/VSYNC value S is the leftmost (earliest) code in the group.
24 bit mode:
Group size = 1 pixel; 1 fragment.
Fragment HS/VS
value
8C0
S
30 bit mode:
In 30-bit mode, if the Video Data Period ends before the pixel group boundary, the remaining
fragments are filled using one or more steps from the 10PCn sequence listed in the table below
until the group boundary is reached (step 10PC4). After that, the normal sequence is used (steps
10Cn).
Group size = 4 pixels; 5 fragments.
Fragment HS/VS
value
10C0
S
10C1
T
10C2
U
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10C4
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V
V
30-bit mode remnant (Falling Edge of DE occurs mid-group). Bridge states for transition from 10Pn
to 10C0 are named “10PCn”:
Fragment HS/VS
value
10PC2
T
10PC3
U
10PC4
V
36 bit mode:
Group size = 2 pixels; 3 fragment.
Fragment HS/VS
value
12C0
S
12C1
T
12C2
T
48 bit mode:
Group size = 1 pixel; 2 fragment.
Fragment HS/VS
value
16C0
S
16C1
S
6.5.3
Deep Color Mode / Phase Indication
When in a Deep Color mode, the Source and Sink each records the packing phase of the last pixel
character of a Video Data period. The Source occasionally sends a General Control Packet (GCP)
communicating the current color depth and the packing phase of the last pixel character sent prior
to the GCP. This data is valid in the GCP whenever CD (CD0, CD1, CD2, CD3) is non-zero.
Whenever the Sink receives a GCP with non-zero CD data, it should compare the receiver’s own
color depth and phase with the CD data. If they do not match, the Sink should adjust its color
depth and/or phase to match the CD data.
When transmitting Deep Color, the Source shall send a General Control Packet (GCP) with an
accurate CD field indicating the current color depth and with the PP field (PP0, PP1, PP2, PP3)
indicating the packing phase of the last pixel character (within the last Video Data Period) sent
prior to the GCP. Sources shall only send GCPs with non-zero CD to Sinks that indicate support
for Deep Color, and shall only select color depths supported by the Sink.
Once a Source sends a GCP with non-zero CD to a sink, it should continue sending GCPs with
non-zero CD at least once per video field even if reverting to 24-bit color, as long as the Sink
continues to support Deep Color.
If the Sink does not receive a GCP with non-zero CD for more than 4 consecutive video fields, it
should exit deep color mode (revert to 24-bit color).
Color Depth field (CD) of SB1:
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When CD is zero, no information about color depth is indicated. PP shall be zero.
When CD is non-zero, the color depth is indicated and the packing phase bits (PP) are valid.
Table 6-1 Color Depth (CD field) Values
CD3
CD2
CD1
CD0
0
0
0
0
Color Depth not indicated
0
0
0
1
Reserved
0
0
1
0
Reserved
0
0
1
1
Reserved
0
1
0
0
24 bits per pixel
0
1
0
1
30 bits per pixel
0
1
1
0
36 bits per pixel
0
1
1
1
48 bits per pixel
All other values
Color Depth
Reserved
A CD field of zero (Color Depth not indicated) shall be used whenever the Sink does not indicate
support for Deep Color. This value may also be used in Deep Color mode to transmit a GCP
indicating only non-Deep Color information (e.g. AVMUTE).
When the CD field indicates 24 bits per pixel, the PP field is invalid and should be ignored by the
Sink.
Pixel Packing Phase field (PP) of SB1:
When the CD field is zero, the PP field shall also be zero.
When the CD field is non-zero, the PP field indicates the packing phase of the last fragment in
the most recent Video Data Period (prior to the GCP message).
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Table 6-2 shows the specific PP values for each of the packing phases shown in the packing phase tables
earlier.
Table 6-2 Pixel Packing Phase (PP field) Values
PP3
PP2
PP1
PP0
0
0
0
0
Phase 4 (10P4)
0
0
0
1
Phase 1 (10P1, 12P1, 16P1)
0
0
1
0
Phase 2 (10P2, 12P2)
0
0
1
1
Phase 3 (10P3)
0
1
0
0
Reserved
All other values
Pixel packing Phase
Reserved
Packing phase 0 does not need to be indicated using the PP bits. This is not necessary as phase 0
always represents only part of the first pixel of the group and therefore, no Video Data Period will
end at phase 0. If the active video ended after the first pixel, then the final phase will be phase 1,
containing the last bits of the first pixel.
If the transmitted video format has timing such that the phase of the first pixel of every Video Data
Period corresponds to pixel packing phase 0 (e.g. 10P0, 12P0, 16P0), the Source may set the
Default_Phase bit in the GCP. The Sink may use this bit to optimize it’s filtering or handling of the
PP field.
Default_Phase field of GCP SB2:
When Default_Phase is 0, the PP bits may vary and the first pixel of each Video Data Period
may vary.
When Default_Phase is 1, the following will be true:
The first pixel of each Video Data Period shall always have a pixel packing phase of 0
(10P0, 12P0, 16P0).
The first pixel following each Video Data Period shall have a pixel packing phase of 0
(10C0, 12C0, 16C0).
The PP bits shall be constant for all GCPs and will be equal to the last packing phase
(10P4, 12P2, 16P1).
The first pixel following every transition of HSYNC or VSYNC shall have a pixel packing
phase of 0 (10C0, 12C0, 16C0).
6.5.4
Pixel Repetition
During pixel-doubling (Pixel_Repetition_Count = 1), all of the data sent across during the first pixel
period will be repeated during the second pixel period. The third pixel period will then represent the
second actual pixel and so on. This is shown below for YCBCR 4:2:2.
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Y0 / CB0
Y0 / CB0
Y1 / CR0
Y1 / CR0
Y2 / CB2
…
Bits 3-0
Y0 bits 3-0
Y0 bits 3-0
Y1 bits 3-0
Y1 bits 3-0
Y2 bits 3-0
…
Bits 7-4
CB0 bits 3-0
CB0 bits 3-0
CR0 bits 3-0
CR0 bits 3-0
CB2 bits 3-0
…
1
Bits 7-0
Y0 bits 11-4
Y0 bits 11-4
Y1 bits 11-4
Y1 bits 11-4
Y2 bits 11-4
…
2
Bits 7-0
CB0 bits 11-4
CB0 bits 11-4
CR0 bits 11-4
CR0 bits 11-4
CB2 bits 11-4
…
TMDS
Channel
0
Figure 6-4 YCBCR 4:2:2 with Pixel-Doubling
Pixel repetition is permitted in conjunction with Deep Color modes. The Source replicates the
pixels as described above prior to Deep Color packing into multiple fragments.
6.6
Video Quantization Ranges
Black and white levels for video components shall be either “Full Range” or “Limited Range.”
Limited Range shall be used for all video formats defined in CEA-861-D, with the exception of
VGA (640x480) format, which requires Full Range.
If the sink’s EDID declares a selectable YCC Quantization Range (QY=1), then it shall expect
limited range pixel values if it receives AVI YQ=0 and it shall expect full range pixel values if it
receives AVI YQ=1. For other values of YQ, the sink shall expect pixel values with the default
range for the transmitted video format.
Table 6-3 Video Color Component Ranges
Color
Component
Component
Bit Depth
for Full range
Black
Nominal Peak
level
(White level)
for Limited range
Nominal Peak
Black level
(White level)
R/G/B
8
0
255
16
235
1 to 254
R/G/B
10
0
1023
64
940
4 to 1019
R/G/B
12
0
4095
256
3760
16 to 4079
R/G/B
16
0
65535
4096
60160
256 to 65279
Color
Component
Component
Bit Depth
Y
CB / CR
Y
CB / CR
Y
CB / CR
Y
CB / CR
8
10
12
16
for Full range
Black
Nominal Peak
level
(White level)
0
255
128
0 and 255
0
1023
512
0 and 1023
0
4095
2048
0 and 4095
0
65535
32768
0 and 65535
Valid Range
for Limited range
Nominal Peak
Black level
(White level)
16
235
128
16 and 240
64
940
512
64 and 960
256
3760
2048
256 and 3840
4096
60160
32768
4096 and 61440
Valid Range
1 to 254
4 to 1019
16 to 4079
256 to 65279
For component ranges for xvYCC, please refer to IEC 61966-2-4.
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6.7
Colorimetry
6.7.1
Default Colorimetry
Version 1.4b
Sources will typically use the specific default colorimetry for the video format being transmitted. If
no colorimetry is indicated in the AVI InfoFrame’s C field (C1, C0) then the colorimetry of the
transmitted signal shall match the default colorimetry for the transmitted video format.
6.7.1.1
480p, 480i, 576p, 576i, 240p and 288p
The default colorimetry for all 480-line, 576-line, 240-line, and 288-line video formats described in
CEA-861-D is based on SMPTE 170M.
6.7.1.2
1080i, 1080p and 720p
The default colorimetry for high-definition video formats (1080i, 1080p and 720p) described in
CEA-861-D is based on ITU-R BT.709-5.
6.7.1.3
Other Formats
The default colorimetry of other video formats is sRGB.
6.7.2
Applicable Colorimetry Standards
6.7.2.1
SMPTE 170M / ITU-R BT.601
For any video categorized as SMPTE 170M, ITU-R BT.601-5 Section 3.5 shall be used for any
color space conversion needed in the course of processing.
The encoding parameter values shall be as defined in Table 3 of ITU-R BT.601-5 and as
summarized in Section 6.6.
6.7.2.2
ITU-R BT.709-5
For any video categorized as ITU-R BT.709, Part 2, Section 3 of that document shall be used for
any color space conversion needed in the course of processing.
The digital representation shall be as defined in Part 2, Section 5.6 of ITU-R BT.709-5 and as
summarized in Section 6.6 above.
6.7.2.3
IEC 61966-2-4 (xvYCC)
IEC 61966-2-4 defines the "Extended-gamut YCC color space for video applications". It is based
on the YCC color encoding described in ITU-R BT.709-5 but extends its definition to a much wider
gamut.
xvYCC601 is based on the colorimetry defined in ITU-R BT.601, and xvYCC709 is based on the
colorimetry defined in ITU-R BT.709.
Refer to Chapter 4.3 of IEC 61966-2-4 for more details.
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Any Source transmission of xvYCC video (either xvYCC601 or xvYCC709) shall be accompanied by
the transmission of valid gamut boundary metadata.
If the attached Sink does not support xvYCC or does not support Gamut Metadata Packets, then
the Source should not transmit xvYCC-encoded video and shall not indicate xvYCC601 or
xvYCC709 in the AVI InfoFrame.
6.7.2.4
IEC 61966-2-1 /Amendment 1 (sYCC601)
The sYCC601 color space is defined in Annex F of IEC 61966-2-1/Amendment 1. The ITU-R Rec.
BT.601 color conversion matrix is used to transform RGB values to YCC values. The sYCC601
color space can represent colors outside of the sRGB color gamut.
Refer to Chapter F.5 of IEC 61966-2-1/Amendment 1 for more details.
If the attached Sink does not support sYCC601, then the Source shall not transmit
sYCC601-encoded video and shall not indicate sYCC601 in the AVI InfoFrame.
6.7.2.5
IEC 61966-2-5 (AdobeRGB, AdobeYCC601)
The AdobeRGB (opRGB) color space is defined in IEC 61966-2-5. See also the Adobe RGB (1998)
Color Image Encoding Specification.
The AdobeYCC601 color space is defined in Annex A of IEC 61966-2-5. The ITU-R Rec. BT.601 color
conversion matrix is used to transform RGB values to YCC values.
If the attached Sink does not support Adobe, then the Source shall not transmit Adobe-encoded
video and shall not indicate AdobeRGB or AdobeYCC601 in the AVI InfoFrame.
6.7.3
Gamut-Related Metadata
HDMI has the ability to carry a description of the video gamut boundary using the Gamut Metadata
Packet.
The Sink indicates support for specific transmission profiles by setting one or more of the MD0,
MD1, etc. bits in the Colorimetry Data Block.
If the attached Sink’s EDID does not include a Colorimetry Data Block then the Source shall not
transmit Gamut Metadata Packets. Note that xvYCC colorimetry requires transmission of the
gamut metadata.
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7
Audio
7.1
Relationship with IEC 60958/IEC 61937
Version 1.4b
L-PCM and IEC 61937 compressed audio data is formatted in the Audio Sample Packet or in the
High Bitrate Audio Stream Packet as a structure that closely resembles an IEC 60958 frame.
(Note: One Bit Audio and DST use a different mechanism – see the overview in sections 7.9.)
On HDMI, each IEC 60958 sub-frame is represented as a 28-bit word. There is no encoding of the
preamble type, which instead is replaced with a “B” bit (start-of-block) in each Audio Sample
packet. The B bit shall be set for a “B, W” frame and shall be clear for an “M, W” frame. (IEC
60958-1 Section 4.1.2). No other sub-frame preamble combinations are allowed.
Except where specifically indicated in this document, the behavior of all fields within the Audio
Sample Subpackets shall follow the corresponding rules specified in the IEC 60958 or IEC 61937
specifications.
HDMI supports any IEC 61937 compressed audio format with a maximum bitrate of 6.144Mbps
(frame rate of 192kHz) or less using Layout 0 of the Audio Sample Packet and higher bitrates
using the HBR Audio Stream Packet (defined in section 5.3.11). See section 7.6 for more details.
An HDMI Source or Sink may support an IEC 61937-compliant compressed audio format that has
an Audio Format Code as specified per CEA-861-D, table 37.
When receiving multi-channel audio, the Sink should not assume that Channel Status bits carried
in Subpackets other than Subpacket 0 will have valid data.
7.2
Audio Sample Clock Capture and Regeneration
Audio data being carried across the HDMI link, which is driven by a TMDS clock running at a rate
corresponding to the video pixel rate, does not retain the original audio sample clock. The task of
recreating this clock at the Sink is called Audio Clock Regeneration.
There are a variety of clock regeneration methods that can be implemented in an HDMI Sink, each
with a different set of performance characteristics. This specification does not attempt to define
exactly how these mechanisms operate. It does however present a possible configuration and it
does define the data items that the HDMI Source shall supply to the HDMI Sink in order to allow
the HDMI Sink to adequately regenerate the audio clock. It also defines how that data shall be
generated.
In many video source devices, the audio and video clocks are generated from a common clock
(coherent clocks). In this situation, there exists a rational (integer divided by integer) relationship
between these two clocks. The HDMI clock regeneration architecture can take advantage of this
rational relationship and can also work in an environment where there is no such relationship
between these two clocks, that is, where the two clocks are truly asynchronous or where their
relationship is unknown.
Figure 7-1 Audio Clock Regeneration model, illustrates the overall system architecture model used
by HDMI for audio clock regeneration. The Source shall determine the fractional relationship
between the TMDS clock and an audio reference clock (128 audio sample rate [fs]) and shall
pass the numerator and denominator of that fraction to the Sink across the HDMI link. The Sink
may then recreate the audio clock from the TMDS clock by using a clock divider and a clock
multiplier.
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The exact relationship between the two clocks will be:
128fS = fTMDS_clock N / CTS.
The Source shall determine the value of the numerator N as specified in Section 7.2.1. Typically,
this value N will be used in a clock divider to generate an intermediate clock that is slower than the
128fS clock by the factor N. The Source will typically determine the value of the denominator CTS
(Cycle Time Stamp) by counting the number of TMDS clocks in each of the 128fS/N clocks.
If there is a constant fractional relationship between these two clocks, and the two clocks are
exactly synchronous, then the CTS value will quickly come to a constant value. If the clocks are
asynchronous, or there is some amount of jitter between the two clocks, then the CTS value will
typically alternate between two or three different values. Greater variations are possible with larger
jitter.
Source Device
Divide
by
N
128*fS
Sink Device
CTS*
Cycle
Time
Counter
Clock
Multiply
by
N
128*f S
N*
Register
N
N
Divide
by
CTS
TMDS
Video Clock
Note: N and CTS values are tran smitted usin g the
"Aud io Cloc k Regene ration" Pac ke t. Video Clock
is trans mitte d on TMDS Clo ck Chane l.
Figure 7-1 Audio Clock Regeneration model
Sink Device
CTS
TMDS Clock
Divide
by
CTS
LowPass
Filter
Phase
Detector
VCO
128*f S
Divide
by N
N
Figure 7-2 Optional Implementation: Audio Sink
It is expected that most Sinks will be implemented with an architecture similar to that shown in
Figure 7-2, however, it is permitted and possible to devise an audio clock regeneration function
that does not take advantage of the N or CTS values passed to the Sink.
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Note that the ACR mechanism uses the TMDS clock, not the pixel clock. When transmitting
normal 24-bit pixels, the two are equivalent but when transmitting Deep Color modes, the TMDS
clock, used for the ACR, will be running at a higher rate than the pixel clock.
It is recommended that Source devices be designed to support integer CTS values whenever
possible.
7.2.1
N parameter
N shall be an integer number and shall meet the following restriction:
128fS / 1500Hz ≤ N ≤ 128fS / 300Hz
with a recommended optimal value of
128fS / 1000Hz approximately equals N
For coherent audio and video clock Sources, the tables in section 7.2.3 below should be used to
determine the value of N. For non-coherent Sources or Sources where coherency is not known,
the equations above should be used.
7.2.2
CTS parameter
CTS shall be an integer number that satisfies the following:
(Average CTS value) = (fTMDS_clock N ) / (128 fS)
7.2.3
Recommended N and Expected CTS Values
The recommended value of N for several standard TMDS clock rates are given in Table 7-1, Table
7-2, and Table 7-3. It is recommended that Sources with non-coherent clocks use the values listed
for a TMDS clock of “Other”.
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Table 7-1 Recommended N and Expected CTS for 32kHz
32 kHz
TMDS Clock
(MHz)
N
CTS
25.2 / 1.001
4576
28125
25.2
4096
25200
27
4096
27000
27 1.001
4096
27027
54
4096
54000
54 1.001
4096
54054
11648
210937-210938*
4096
74250
11648
421875
148.5
4096
148500
297 / 1.001
5824
421875
297
3072
222750
Other
4096
Measured
74.25 / 1.001
74.25
148.5 / 1.001
* Note: This value will alternate because of restriction on N.
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Table 7-2 Recommended N and Expected CTS for 44.1kHz and Multiples
44.1 kHz
TMDS Clock
(MHz)
88.2 kHz
176.4 kHz
N
CTS
N
CTS
N
CTS
25.2 / 1.001
7007
31250
14014
31250
28028
31250
25.2
6272
28000
12544
28000
25088
28000
27
6272
30000
12544
30000
25088
30000
27 1.001
6272
30030
12544
30030
25088
30030
54
6272
60000
12544
60000
25088
60000
54 1.001
6272
60060
12544
60060
25088
60060
17836
234375
35672
234375
71344
234375
74.25
6272
82500
12544
82500
25088
82500
148.5 / 1.001
8918
234375
17836
234375
35672
234375
148.5
6272
165000
12544
165000
25088
165000
297 / 1.001
4459
234375
8918
234375
17836
234375
297
4704
247500
9408
247500
18816
247500
Other
6272
measured
12544
measured
25088
measured
74.25 / 1.001
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Table 7-3 Recommended N and Expected CTS for 48kHz and Multiples
48 kHz
TMDS Clock
(MHz)
96 kHz
192 kHz
N
CTS
N
CTS
N
CTS
25.2 / 1.001
6864
28125
13728
28125
27456
28125
25.2
6144
25200
12288
25200
24576
25200
27
6144
27000
12288
27000
24576
27000
27 1.001
6144
27027
12288
27027
24576
27027
54
6144
54000
12288
54000
24576
54000
54 1.001
6144
54054
12288
54054
24576
54054
11648
140625
23296
140625
46592
140625
74.25
6144
74250
12288
74250
24576
74250
148.5 / 1.001
5824
140625
11648
140625
23296
140625
148.5
6144
148500
12288
148500
24576
148500
297 / 1.001
5824
281250
11648
281250
23296
281250
297
5120
247500
10240
247500
20480
247500
Other
6144
measured
12288
measured
24576
measured
74.25 / 1.001
7.2.4
L-PCM and IEC 61937 Compressed Audio ACR
For any L-PCM stream, the ACR fS value shall be equal to the audio sample rate.
For any IEC 61937 compressed audio with an IEC 60958 frame rate at or below 192kHz, the ACR
fS value shall be equal to the frame rate. For any such stream with an IEC 60958 frame rate above
192kHz, the ACR fS value shall be 1/4th of the frame rate.
7.2.5
One Bit Audio ACR
For any One Bit Audio stream, the ACR fS value shall be 1/64th of the bit rate. For One Bit Audio
data from Super Audio CD (2.8224MHz) the ACR fS would therefore be 44.1kHz.
7.2.6
DST Audio ACR
For DST audio streams, the ACR fS corresponds to the sample rate of the underlying compressed
audio samples, which is typically 64*44.1kHz (2.8224MHz). This is true whether DST_Normal or
DST_Double rate is used.
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Audio Sample Rates and Support Requirements
If an HDMI Source supports audio transmission across any output, then it shall support HDMI
audio transmission. Exceptions to this rule for Sources with Type B connectors are found in
Appendix B.
An HDMI Source is permitted to transmit L-PCM audio data at sample rates of 32kHz, 44.1kHz,
48kHz, 88.2kHz, 96kHz, 176.4kHz or 192kHz.
An HDMI Source is permitted to transmit IEC 61937 compressed audio at any IEC 60958 frame
rate listed in Table 7-4.
If an HDMI Source supports any HDMI audio transmission, then it shall support 2 channel L-PCM
(using an IEC 60958 Subpacket structure), with either 32kHz, 44.1kHz or 48kHz sampling rate and
a sample size of 16 bits or more.
Transmitted audio shall have an audio sample rate (fS) within 1000 ppm of the sample rate
indicated in Channel Status bits 24 through 27, except when the Source is Audio Rate Controlled
by CEC (see section 7.11).
If an HDMI Sink supports audio reception from any input, then it shall support audio reception from
all HDMI inputs.
An HDMI Sink may accept L-PCM audio at sample rates of 32kHz, 44.1kHz, 48kHz, 88.2kHz,
96kHz, 176.4kHz or 192kHz, and should indicate these capabilities in the E-EDID data structure.
An HDMI Sink may accept IEC 61937 compressed audio at any IEC 60958 frame rate listed in
Table 7-4, and should indicate these capabilities in the E-EDID data structure.
An HDMI Sink that is capable of accepting any audio format is required to accept two channel (IEC
60958-formatted) L-PCM audio at sample rates of 32kHz, 44.1kHz, and 48kHz.
A Sink shall support the reception of an audio stream with correct sample rate indication in
Channel Status bits 24 through 27 and with a sample rate (fS) within 1000 ppm of any supported
sample rate. There is no sample size usage restriction for Sinks.
For CEA-861-D references to Sources, “Basic Audio” is defined as two channel L-PCM audio at
sample rates of 32kHz, 44.1kHz, or 48kHz, with a sample size of at least 16 bits. For CEA-861-D
references to DTV devices, “Basic Audio” is defined as two channel L-PCM audio at sample rates
of 32kHz, 44.1kHz, and 48kHz.
An HDMI Repeater shall support HDMI audio reception and transmission.
Whenever transmitting a valid audio stream, HDMI Sources shall always include valid and correct
information in Channel Status bits 24 through 27. For L-PCM audio, these bits shall indicate the
audio sample frequency. For compressed audio formats, these bits shall indicate the IEC 60958
frame rate. An HDMI audio stream shall only indicate values shown in Table 7-4. Note that the
allowed values do not include the IEC 60958-specified “Sample frequency not indicated” value.
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Table 7-4 Allowed Values for Channel Status bits 24 to 27
Channel Status Bit Number
24
25
26
27
Sample
Frequency or
Frame Rate
1
1
0
0
32 kHz
0
0
0
0
44.1 kHz
0
0
0
1
88.2 kHz
0
0
1
1
176.4 kHz
0
1
0
0
48 kHz
0
1
0
1
96 kHz
0
1
1
1
192 kHz
1
0
0
1
768 kHz
Note that rates of 352.8 kHz, 384 kHz, 705.6 kHz are not yet supported by IEC 60958. When this
happens, these rates may be supported by an HDMI Source or Sink.
In some cases, pixel-repetition may be required to increase the available bandwidth for audio
transmission. For instance, when transmitting a 720x480p video format timing, it is required to
pixel double in order to transmit 6 channels @ 96kHz.
7.3.1
One Bit Audio Sample Rate Requirements
A Source may transmit One Bit Audio at an fS (1/64th of the bit rate) of 32kHz, 44.1kHz, 48kHz,
88.2kHz, 96kHz, 176.4kHz or 192kHz. Any Source capable of supporting One Bit Audio should
support an fS of 44.1kHz, corresponding to a bit rate of 2.8224MHz.
Transmitted One Bit Audio shall have an audio sample rate within ±1000 ppm of the targeted
sample rate, except when the Source is Audio Rate Controlled by CEC (see section 7.11).
A Sink may accept One Bit Audio at an fS (1/64th of the bit rate) of 32kHz, 44.1kHz, 48kHz,
88.2kHz, 96kHz, 176.4kHz or 192kHz. Any Sink capable of supporting One Bit Audio shall support
an fS of 44.1kHz, corresponding to a bit rate of 2.8224MHz.
For One Bit Audio, sample frequency information is carried in the Audio InfoFrame (see section
8.2.2).
7.3.2
DST Audio Sample Rate Requirements
All current DST streams carry compressed one bit audio samples with an actual (DAC) sampling
frequency of 64*44.1kHz (2.8224MHz).
Any Source capable of supporting DST may transfer DST streams using either DST_Normal or
DST_Double rate transmission.
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Transmitted DST shall have an audio sample rate within ±1000 ppm of the targeted sample rate,
except when the Source is Audio Rate Controlled by CEC (see section 7.11).
Any Sink capable of supporting DST shall support streams with a sample rate of 64*44.1kHz (an fS
of 44.1kHz), and shall support reception of both DST_Normal and DST_Double rate.
7.3.3
Video Dependency
Available audio bandwidth depends upon the TMDS clock frequency, the video format timing, and
whether or not content protection re-synchronization is needed.
Table 7-5 shows the available audio sample rates for 2-channel (Layout 0) and 8-channel (Layout
1) audio transmission at the various video format timings specified in CEA-861-D, assuming that
58 TMDS clocks of the horizontal blanking interval is required for content protection
re-synchronization.
Table 7-5 Max Sampling Frequency for 24-bit Video Format Timings* (Informative)
SuperAudio
Max frame
CD Channel
rate
Count
2 ch, comp**
Description
Format
Timing
Pixel
Repetition
Vertical Freq
(Hz)
Max fS
8 ch (kHz)
VGA
640x480p
none
59.94/60
48
192
2
480i
1440x480i
2
59.94/60
88.2
192
2
480i
2880x480i
4
59.94/60
192
768
8
240p
1440x240p
2
59.94/60
88.2
192
2
240p
2880x240p
4
59.94/60
192
768
8
480p
720x480p
none
59.94/60
48
192
2
480p
1440x480p
2
59.94/60
176.4
384
8
480p
2880x480p
4
59.94/60
192
768
8
720p
1280x720p
none
59.94/60
192
768
8
1080i
1920x1080i
none
59.94/60
192
768
8
1080p
1920x1080p
none
59.94/60
192
768
8
480i / 120Hz
1440x480i
2
119.88/120
176.4
384
8
480p / 120Hz
720x480p
none
119.88/120
96
384
8
50Hz Formats
576i
1440x576i
2
50
88.2
192
2
576i
2880x576i
4
50
192
768
8
288p
1440x288p
2
50
88.2
192
2
288p
2880x288p
4
50
192
768
8
576p
720x576p
none
50
48
192
2
576p
1440x576p
2
50
176.4
384
8
576p
2880x576p
4
50
192
768
8
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720p/50
1280x720p
none
50
192
768
8
1080i/50
1920x1080i
none
50
192
768
8
1080p/50
1920x1080p
none
50
192
768
8
1080i, 1250 total
1920x1080i
none
50
192
768
8
576i / 100Hz
1440x576i
2
100
176.4
384
8
576p / 100Hz
720x576p
none
100
96
384
8
1080p
1920x1080p
None
24
192
768
8
1080p
1920x1080p
None
25
192
768
8
1080p
1920x1080p
None
29.97/30
192
768
8
1080p @ 24-30Hz
* Note that formats listed in Section 6.3 but not listed above can carry 8 channels at 192kHz or 8 channels of
One Bit Audio at the SuperAudio CD rate.
** Note that 2-channel PCM can never exceed 192kHz. Higher values in this column indicate higher frame
rates that can be used for compressed streams. Note that 384kHz is not currently supported by IEC 60958.
7.4
Channel / Speaker Assignment
HDMI allows a Sink to indicate the configuration of attached speakers through the use of the
Speaker Allocation Data Block described in CEA-861-D section 7.5.3. Sinks supporting
multi-channel L-PCM or multi-channel One Bit Audio shall include this Data Block.
In addition, for L-PCM or One Bit audio streams, the Source shall specify the speaker assignment
for each of the channels in the audio stream delivered to the Sink. CEA-861-D section 6.6
specifies the available speaker assignments for active audio channels on HDMI. The indication of
the current speaker assignment is carried in the CA field of the Audio InfoFrame.
7.5
Audio, Video Synchronization
For a variety of reasons, an HDMI link may add a delay to the audio and/or video.
An HDMI Source shall be capable of transmitting audio and video data streams with no more than
±2 msec of audio delay relative to the video. Due to the uneven transmission of audio data, the
delay shall be considered to be the average delay of all of the audio sample packets over the
course of 3 steady-state video frames.
7.6
Audio Data Packetization
Each Subpacket of an Audio Sample Packet shall contain zero or one IEC 60958-defined “frames”
of an IEC 60958 or IEC 61937 “block.” There are two defined Subpacket layouts. No others are
permitted.
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Table 7-6 Audio Packet Layout and Layout Value
Layout
Value
Max Num
Channels
Samples
Subpkt 0
Subpkt 1
Subpkt 2
Subpkt 3
0
2
4
Chnl
1,2
Sample 0
Chnl
1,2
Sample 1
Chnl
1,2
Sample 2
Chnl
1,2
Sample 3
1
8
1
Chnl
1,2
Sample 0
Chnl
3,4
Sample 0
Chnl
5,6
Sample 0
Chnl
7,8
Sample 0
There are four sample_present bits in the Audio Sample Packet Header, one for each of the
Subpackets. These indicate if that Subpacket contains audio sample(s).
In addition, there are four sample_flat.spX bits which are set if no useful audio data was available
at the Source during the time period represented by that sample. This may occur during sample
rate changes or temporary stream interruptions. When sample_flat.spX is set, Subpacket X
continues to represent a sample period but does not contain useful audio data. The
sample_flat.spX bit is only valid when the corresponding sample_present.spX bit is set.
Layout 0 can be used to carry up to four samples from a single IEC 61937 or from a single
2-channel IEC 60958 stream of audio.
There are only five valid configurations of sample_present bits for a Layout 0 Audio Packet. They
are shown in Table 7-7.
Table 7-7 Valid Sample_Present Bit Configurations for Layout 0
SP0
SP1
SP2
SP3
Description
0
0
0
0
No Subpackets contain audio samples.
1
0
0
0
Only Subpacket 0 contains audio samples.
1
1
0
0
Subpackets 0 and 1 contain audio samples.
1
1
1
0
Subpackets 0, 1, and 2 contain audio samples.
1
1
1
1
All Subpackets contain audio samples.
Layout 1 can be used to carry one audio sample with three to eight channels of L-PCM audio (i.e.
two to four IEC 60958 streams).
Valid combinations of sample_present bits for Layout 1 Audio Packets are determined by the
permitted channel allocations as described in CEA-861-D section 6.6.
An HDMI Source shall place the data shown into the specified Subpackets and to identify the
layout in the Audio Sample Packet Header.
The fields within a Subpacket with a corresponding sample_flat bit set or a sample_present bit
clear, are not defined and can be any value.
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Figure 7-3 Example Audio Sample Timing (Informative)
7.6.1
One Bit Audio Packetization
When transmitting One Bit Audio, each Subpacket shall contain One Bit Audio bits for zero, one or
two audio channels.
There are four sample_present bits in the One Bit Audio Sample Packet Header, one for each of
the Subpackets. The corresponding bit is set if that Subpacket contains audio samples. There are
four samples_invalid.spX bits which are set if no useful audio data was available at the Source
during the time period represented by that sample. When samples_invalid.spX is set, Subpacket X
continues to represent a sample period but does not contain any useful data.
Layout 0 can be used to carry 2 channels of One Bit Audio samples. Layout 1 can be used to carry
from three to eight channels of One Bit Audio samples.
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Valid combinations of sample_present bits for Layout 1 Audio Packets are determined by the
permitted channel allocations as described in section 7.6 above.
The fields within a Subpacket with a corresponding samples_invalid bit set or a sample_present bit
clear, are not defined and can be any value.
7.6.2
High-Bitrate Audio Stream Packetization
When carrying IEC 61937 compressed audio at frame rates above 192kHz, the HBR Audio
Stream packet shall be used.
Each Subpacket of a High-Bitrate Audio Stream Packet shall contain one IEC 60958-defined
“frame” of an IEC 61937 bitstream.
Table 7-8 High Bitrate Audio Stream Packet Layout
Subpkt 0
Subpkt 1
Subpkt 2
Subpkt 3
Frame x+0
Frame x+1
Frame x+2
Frame x+3
For many high bitrate streams (e.g. DTS-HD Master Audio and Dolby MAT), the IEC 61937 data
bursts will always have a repetition period that is a multiple of four frames, and so the Pa and Pb
syncwords will always be found in the same subpacket. In such cases, the codec vendor may
impose the additional constraint that Pa and Pb always appear in subpacket 0.
7.6.3
DST Packetization
The DST audio stream consists of a series of frames, each of which carries audio data for 1/75th of
a second. Each DST frame will be transmitted using a number of DST Audio Packets. The end of a
DST frame may occur within a DST Audio Packet. Any unused bits in such a DST Audio Packet
shall be padded with “0”. In the time between the completion of one DST Audio Frame and the
start of the next, DST Audio Packets containing all “0” shall be sent. A new DST Audio Packet with
the frame_start bit set to “1” in the header shall be used when the next DST Audio Frame starts
and the first bit of the new DST frame data shall be placed in D.0 of the packet body.
When samples_invalid in the DST Audio Packet is set to “1”, then the data in the DST Audio
Packet is not valid or does not contain any useful data.
7.7
Error Handling (Informative)
The behavior of the Sink after detecting an error is implementation-dependent. However, Sinks
should be designed to prevent loud spurious noises from being generated due to errors. Sample
repetition and interpolation are well known concealment techniques and are recommended.
7.8
Packet Delivery Rules
7.8.1
Audio Sample Packets
All audio samples that are stored in a source buffer shall be sent as soon as possible while still
fulfilling requirements for audio/video synchronization, and Data Island timing and placement.
When using Layout 0 Audio Sample Packets, the Source shall transmit an Audio Sample Packet if
at least one sample is stored in the source buffer.
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Relative to an ideal constant-frequency clock, the jitter present in the Audio Sample Packet
transmission timing shall not exceed one horizontal line period plus a single audio sample period.
7.8.2
Audio Clock Regeneration Packets
Nominally, Audio Clock Regeneration Packets with newly generated CTS values will be
transmitted at a rate of 128fS/N. On average, the Source shall transmit CTS values at this rate
precisely. The Source shall transmit each CTS data value as close as possible to the nominal
transmission time for that value with the exception that priority must be given to Audio Sample
packets to ensure that Audio Sample Packet delivery requirements are met.
7.9
One Bit Audio Usage Overview
One Bit Audio data is transmitted using the One Bit Audio packet defined in section 5.3.9 and
described in section 7.6.1.
One Bit Audio clock regeneration uses the same mechanism used for all audio on HDMI and is
described in section 7.2.5. One Bit Audio sample rate requirements are described in section 7.3.1.
A Sink may indicate its support for One Bit Audio with the Short Audio Descriptor as described in
section 8.3.6.
One Bit Audio uses some fields within the Audio InfoFrame differently than L-PCM or compressed
audio; these differences are described in section 8.2.2.
7.10
DST Usage Overview
DST data is transmitted using the DST Sample packet defined in section 5.3.10 and described in
section 7.6.3.
DST clock regeneration uses the same mechanism used for all audio on HDMI and is described in
section 7.2.6. DST Audio sample rate requirements are described in section 7.3.2.
A Sink may indicate its support for DST with the Short Audio Descriptor as described in section
8.3.6.
In some cases, DST uses some fields within the Audio InfoFrame differently than L-PCM or IEC
61937 compressed audio; these differences are described in section 8.2.2.
7.11
Audio Rate Control Overview
The Audio Rate Control feature allows a Sink to slightly and continuously adjust the audio clock
rate of the Source in order to match the Sink’s crystal-based audio clock. The Sink controls the
Source’s audio clock rate with the CEC <Set Audio Rate> command. See CEC Supplement
section CEC 13.16 for details.
Source ACR behavior is not affected by Audio Rate Control. When Audio Rate Control is enabled
the Source shall continue to generate correct ACR packets that accurately reflect the current
(possibly adjusted) audio clock rate.
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Audio Return Channel Overview
The Audio Return Channel (ARC) feature allows an HDMI Sink to transmit an IEC 60958-1 audio
stream in the reverse direction to the TMDS path to an HDMI Source or an HDMI Repeater. The
Audio Return Channel is controlled by the use of CEC messages. Once activated through a CEC
message, the Utility line alone (single Mode) or the Utility line in conjunction with the Hot Plug
Detect line (common Mode) may be used for ARC transmission as specified in Supplement 2.
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8
Control And Configuration
8.1
Overview
Version 1.4b
HDMI includes four separate communications channels: TMDS, DDC, and the optional CEC and
HEC.
TMDS is used to carry audio and video data as well as auxiliary data, including AVI and Audio
InfoFrames that describe the active audio and video streams.
The DDC channel is used by an HDMI Source to determine the capabilities and characteristics of
the Sink by reading the E-EDID data structure.
HDMI Sources are expected to read the Sink’s E-EDID and to deliver only the audio and video
formats that are supported by the Sink. In addition, HDMI Sinks are expected to detect InfoFrames
and to process the received audio and video data appropriately.
The CEC channel is optionally used for higher-level user functions such as automatic setup tasks
or tasks typically associated with infrared remote control usage.
HEC is optionally used as a high-speed bidirectional data channel, based on 100Base-TX. For
further information see Supplement 2.
8.2
InfoFrames
An InfoFrame packet carries one InfoFrame. The InfoFrame provided by HDMI is limited to 30
bytes plus a checksum byte. HDMI Sources are required, in some cases, to use the AVI InfoFrame
and Audio InfoFrame and recommended in other cases. Other InfoFrames specified in CEA-861-D
are optional.
All InfoFrames are described in detail in CEA-861-D. The following describes how three of these
InfoFrames are placed within the InfoFrame Packet structure and any areas where HDMI behavior
is different from that specified in CEA-861-D.
8.2.1
Auxiliary Video information (AVI) InfoFrame
Various aspects of the current video stream are indicated by the HDMI Source to the Sink with an
Auxiliary Video information (AVI) InfoFrame.
A Source shall always transmit an AVI InfoFrame at least once per two Video Fields if the Source:
is ever capable of transmitting an AVI InfoFrame or,
is ever capable of transmitting YCBCR pixel encoding or,
is ever capable of transmitting any colorimetry other than the transmitted video format’s
default colorimetry or,
is ever capable of transmitting any xvYCC or future enhanced colorimetry or,
is ever capable of transmitting any Gamut Metadata packet or,
is ever capable of transmitting any video format with multiple allowed pixel repetitions or,
is ever capable of transmitting Content Type other than “no data” or,
is ever capable of transmitting YCC Quantization Range.
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The AVI InfoFrame shall be transmitted even while such a Source is transmitting RGB and
non-pixel-repeated video. When a Source is not explicitly required to transmit AVI InfoFrames, it is
recommended that the Source transmit AVI InfoFrames.
The packetization of the AVI InfoFrame Version 2 is shown below.
Table 8-1 AVI InfoFrame Packet Header
Byte \ Bit #
7
6
5
4
3
2
HB0
Packet Type = 0x82
HB1
Version = 0x02
HB2
0
0
0
1
0
Length = 13 (0x0D)
Table 8-2 AVI InfoFrame Packet Contents
Packet Byte
#
CEA-861-D
Byte #
PB0
n.a..
PB1
Data Byte 1
Rsvd
(0)
Y1
Y0
A0
PB2
Data Byte 2
C1
C0
M1
PB3
Data Byte 3
ITC
EC2
PB4
Data Byte 4
Rsvd
(0)
PB5
Data Byte 5
YQ1
PB6
Data Byte 6
Line Number of End of Top Bar (lower 8 bits)
PB7
Data Byte 7
Line Number of End of Top Bar (upper 8 bits)
PB8
Data Byte 8
Line Number of Start of Bottom Bar (lower 8 bits)
PB9
Data Byte 9
Line Number of Start of Bottom Bar (upper 8 bits)
PB10
Data Byte 10
Pixel Number of End of Left Bar (lower 8 bits)
PB11
Data Byte 11
Pixel Number of End of Left Bar (upper 8 bits)
PB12
Data Byte 12
Pixel Number of Start of Right Bar (lower 8 bits)
PB13
Data Byte 13
Pixel Number of Start of Right Bar (upper 8 bits)
PB14-PB27
n. a.
Reserved (0)
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7
6
5
4
3
2
1
0
B1
B0
S1
S0
M0
R3
R2
R1
R0
EC1
EC0
Q1
Q0
SC1
SC0
VIC6
VIC5
VIC4
VIC3
VIC2
VIC1
VIC0
YQ0
CN1
CN0
PR3
PR2
PR1
PR0
Checksum
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See CEA-861-D section 6.4 for more information on the following fields:
Y0, Y1
A0
Active Information Present. Indicates whether field R0...R3 is valid. See
CEA-861-D table 8 for details.
B0, B1
Bar Info data valid. See CEA-861-D table 8 for details.
S0, S1
details.
Scan Information (i.e. overscan, underscan). See CEA-861-D table 8 for
C0, C1
Colorimetry (ITU BT.601, BT.709 etc.). See CEA-861-D table 9 for details.
M0, M1
Picture Aspect Ratio (4:3, 16:9). See CEA-861-D table 9 for details.
R0...R3 Active Format Aspect Ratio. See CEA-861-D (table 9, table 10 and Annex H)
for details.
ITC
EC0, EC1, EC2
Q0, Q1
SC0, SC1 Non-uniform Picture Scaling. See CEA-861-D table 11.
VIC0...VIC6
Video Format Identification Code.
When transmitting any 2D video format of section 6.3 above, an HDMI Source shall set
the VIC field to the Video Code for that format. See CEA-861-D section 6.4 for details. The
additional VIC values from 60 to 64 are defined in Table 8-4.
When transmitting any 3D video format using the 3D_Structure field in the HDMI Vendor
Specific InfoFrame, an HDMI Source shall set the AVI InfoFrame VIC field to satisfy the
relation described in section 8.2.3.2.
When transmitting any extended video format indicated through use of the HDMI_VIC field
in the HDMI Vendor Specific InfoFrame or any other format which is not described in the
above cases, an HDMI Source shall set the AVI InfoFrame VIC field to zero.
YQ0, YQ1
YCC Quantization Range specified in Table 8-5.
CN0, CN1
Content Type specified by Table 8-6.
PR0...PR3
details.
Pixel Repetition factor. See CEA-861-D table 13 and Table 8-4 for
RGB or YCBCR indicator.
IT Content. See Table 8-6 and CEA-861-D table 11 for details.
Extended Colorimetry (IEC 61966-2-4 etc.). See Table 8-3 for details.
Quantization range (Full vs. Limited, etc.). See CEA-861-D table 11 for details.
Table 8-3 Extended Colorimetry
EC2
EC1
EC0
0
0
0
xvYCC601
0
0
1
xvYCC709
0
1
0
sYCC601
0
1
1
AdobeYCC601
1
0
0
AdobeRGB
1
0
1
Reserved
1
1
0
Reserved
1
1
1
Reserved
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Table 8-4 VIC AVI InfoFrame Packet Contents
VIC value
Formats
Field Rate
Pixel repeat value
60
720p (1280x720)
23.98 / 24
No Repetition
61
720p (1280x720)
25
No Repetition
62
720p (1280x720)
29.97 / 30
No Repetition
63
1080p (1920x1080)
119.88 / 120
No Repetition
64
1080p (1920x1080)
100
No Repetition
Table 8-5 YCC Quantization Range
YQ1
YQ0
YCC Quantization Range
0
0
Limited Range
0
1
Full Range
1
0
Reserved
1
1
Reserved
Table 8-6 Content Type
ITC
CN1,CN0
Content Type
0
0,0
No Data
No Data
Graphics
Graphics (text). This indicates that content is
composed according to common IT practice (i.e.
without regard to Nyquist criterion) and is unsuitable
for analog reconstruction or filtering.
1
0,0
Description
X
0,1
Photo
The Photo type is indicated by the source to flag
content derived from digital still pictures. When the
Photo type is indicated, Extended Colorimetry bits
should correctly indicate the content’s color space.
X
1,0
Cinema
The Cinema type is indicated by the source to flag
content derived from cinema material.
X
1,1
Game
The Game type is indicated by the source to flag
content derived from game machine material.
“X” denotes don’t care.
This Content Type value does not depend on the device category of the source. Only when the
source knows the type of content being sent to the sink to be of Content Types Photo, Cinema,
Game or Graphics, it may set the Content Type field accordingly. Otherwise the source shall set
this field to (0, 0) with ITC=0.
When the source does not know the Content Type, then it shall set the Content Type to “No data”.
At all other times, the Content Type shall accurately indicate the type of content that the source is
sending.
When sending content of a particular Content Type other than Graphics (Photo, Cinema, Game)
and if the attached Sink has set the corresponding CNC flag (CNC1-3) in HDMI Vendor Specific
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Data Block (section 8.3.2) to 0 (to indicate the absence of a processing mode for a particular
Content Type), then the Source shall set ITC = 0 and CN as “no data”, i.e. CN = (0, 0).
When the source has content of Content Type Photo and/or Cinema and if the sink indicates that it
has specific processing for that Content Type (by setting the relevant CNC bit to 1), then the
source should pass through that content with minimal processing and set the Content Type to the
corresponding value.
When the source has content of Content Type Game and if the sink indicates that it has specific
processing for the Game Content Type (by setting the relevant CNC bit to 1), then the source
should set the Content Type to the corresponding value.
When the source has content of Content Type Graphics, and the sink indicates that it has specific
processing for that Content Type (by setting the CNC0 bit to 1), then the source should set ITC = 1
and CN=(0,0) to indicate this Content Type.
Note 1:
a source of version 1.4 or later cannot distinguish between a 1.3 sink and a 1.4 (or later) sink
with CNC0 = 0 and CNC1-3 = all 0s. Therefore, in this case the source cannot check the
CNC bit for type Graphics and can skip the check of CNC0=1 in the above paragraph.
Note 2:
when a sink of version 1.4 or later is connected to a source of version 1.3, the source will not
check the sink’s CNC-bits and can set Content Type to Graphics even if the sink has set the
corresponding CNC bit (CNC0) to 0.
8.2.2
Audio InfoFrame
A Source shall indicate characteristics of the active audio stream using the IEC 60958 Channel
Status bits, IEC 61937 Burst Info and/or stream data (if present) and the Audio InfoFrame.
Whenever an active audio stream is being transmitted, an accurate Audio InfoFrame shall be
transmitted at least once per two Video Fields.
Upon the start of a new audio stream or upon any change in the audio stream that can be
indicated by the Audio InfoFrame, a modified, accurate Audio InfoFrame shall be transmitted no
later than one video field following the first affected non-silent audio sample. Preferably, this would
occur just before the first affected audio sample is transmitted. For One Bit Audio streams, the
Audio InfoFrame shall be transmitted before the first affected sample.
The Audio InfoFrame transmission may occur at any time that a Data Island packet may be
transmitted, including during any horizontal or vertical blanking period.
Note that several of the fields permit a value of 0 (referred to in the CEA-861-D specification as
“Refer to Stream Header”). A value of 0 signifies that the information associated with that field is
actually indicated or implied by other items in the audio stream, for instance, by the IEC 60958
Channel Status bits or the IEC 61937 Burst Info.
The following tables show the packetization of the Audio InfoFrame.
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Table 8-7 Audio InfoFrame Packet Header
Byte \ Bit #
7
6
5
4
3
2
HB0
Packet Type = 0x84
HB1
Version Number = 0x01
HB2
0
0
0
1
0
Length = 10 (0x0A)
Table 8-8 Audio InfoFrame Packet contents
Packet
Byte #
CEA-861-D
Byte #
PB0
n. a.
PB1
Data Byte 1
PB2
Data Byte 2
PB3
Data Byte 3
PB4
Data Byte 4
CA7
CA6
CA5
CA4
CA3
CA2
CA1
CA0
PB5
Data Byte 5
DM_INH
LSV3
LSV2
LSV1
LSV0
Rsvd
(0)
LFEP
BL1
LFEP
BL0
PB6
Data Byte 6
Reserved (0)
PB7
Data Byte 7
Reserved (0)
PB8
Data Byte 8
Reserved (0)
PB9
Data Byte 9
Reserved (0)
PB10
Data Byte 10
Reserved (0)
PB11PB27
n. a.
Reserved (0)
7
6
5
4
3
2
1
0
CT0
Rsvd
CC2
CC1
CC0
SF2
SF1
SF0
SS1
SS0
Checksum
CT3
CT2
CT1
Reserved (0)
Format depends on coding type (i.e. CT0...CT3)
See CEA-861-D section 6.6 for more information on the following fields:
CC0...CC2
CT0...CT3 Coding Type. The CT bits shall always be set to a value of 0 (“Refer to Stream
Header”).
SS0...SS1 Sample Size. The SS bits shall always be set to a value of 0 (“Refer to Stream
Header”).
SF0...SF2 Sample Frequency. See CEA-861-D table 18 for details. For L-PCM and IEC
61937 compressed audio streams, the SF bits shall always be set to a value of 0 (“Refer
to Stream Header”). For One Bit Audio and DST streams, the value indicated by the SF
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bits shall equal the ACR fS value (see sections 7.2.5 and 7.2.6). For Super Audio CD, the
SF bits are typically set to 0, 1, 0, to indicate a Sample Frequency of 2.8224MSamples/s
(i.e. 64*44.1kHz).
CA0...CA7 Channel/Speaker Allocation. See CEA-861-D Section 6.6.2 for details. The CA
field is not valid for IEC 61937 compressed audio streams.
LSV0...LSV3
Level Shift Value (for downmixing). See CEA-861-D Section 6.6.2
and CEA-861-D table 21 for details.
DM_INH Downmix Inhibit. See CEA-861-D section 6.6.2 and table 22 for details. The
DM_INH field is to be set only for DVD-Audio applications and corresponds to the value in
the DM_INH field of the current audio stream being played from the disk. The DM_INH
field value shall be set to zero in all cases other than DVD-Audio applications.
LFEPBL0, LFEPBL1
LFE Playback level information.
Table 8-9 LFE Playback Level Information
LFEPBL1
0
0
1
1
LFEPBL0
0
1
0
1
Describes what value is used for the LFE playback level as
compared to the other channels.
No information
0 dB playback
+ 10 dB playback
Reserved
Data Byte 3 shall always be set to a value of 0.
8.2.3
HDMI Vendor Specific InfoFrame
This is a CEA-861 Vendor Specific InfoFrame containing a 24-bit IEEE Registration Identifier of
0x000C03, a value belonging to HDMI Licensing, LLC. The content of this InfoFrame is defined by
this specification.
The transmission of this InfoFrame is optional for the source device. But if a source device outputs
a video signal which is defined in this section 8.2.3, the source shall transmit this packet.
Whenever this packet is transmitted, an accurate HDMI Vendor Specific InfoFrame shall be
transmitted at least once per two Video Fields.
It is optional for a Sink to interpret this packet. When the Sink receives both HDMI_VIC in the
HDMI Vendor Specific InfoFrame and VIC in the AVI_InfoFrame, then the HDMI_VIC value shall
be used. Other data in the AVI InfoFrame packet remains valid even if the HDMI Vendor Specific
InfoFrame is transmitted.
The packetization of this HDMI Vendor Specific InfoFrame is defined below.
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Table 8-10 HDMI Vendor Specific InfoFrame Packet Header
Byte \ Bit #
7
6
5
4
3
2
HB0
Packet Type = 0x81
HB1
Version = 0x01
HB2
0
0
0
1
0
Length = Nv
Table 8-11 HDMI Vendor Specific InfoFrame Packet Contents
Packet Byte #
7
6
5
4
PB0
3
2
1
0
Rsvd
(0)
Rsvd
(0)
Checksum
PB1
24bit IEEE Registration Identifier (0x000C03)
( least significant byte first )
PB2
PB3
PB4
Rsvd
(0)
HDMI_Video_Format
Rsvd
(0)
Rsvd
(0)
HDMI_VIC
(PB5)
(PB6)
3D_Structure
Reserved(0)
3D_Ext_Data
Reserved(0)
.. PB(Nv)
Reserved (0)
Length
[5bits] This 5 bits field defines the length of HDMI vendor specific InfoFrame
payload.
HDMI_Video_Format
[3bits] This value defines the structure of extended video
formats exclusively defined within this HDMI specification.
Table 8-12 HDMI_Video_Format
Value
[2…0]
description
000
No additional HDMI video format is presented in this packet.
001
Extended resolution format (e.g. used for 4K x 2K video) present.
1 byte of HDMI_VIC parameter value follows.
010
3D format indication present.
3D_Structure, and potentially 3D_Ext_Data, follows.
011 ~ 111
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HDMI_VIC
[1byte] HDMI proprietary Video Format Identification Code. When
transmitting any video format defined in this section 8.2.3.1, an HDMI Source shall set the
HDMI_VIC field to the Video Code for that format. The HDMI_VIC value is defined in
section 8.2.3.1.
3D_Structure
[4bits] This 4 bit field defines the transmission format of 3D video data.
The value of “0000” means the Frame packing structure described in this section. The
value of “1000” means the Side-by-Side (Half) structure described in this section. The
value of “0110” means the Top-and-Bottom 1 structure described in this section. For other
values, see Appendix H (Table H-2).
Table 8-13 3D_Structure
Value
Meaning
0000
Frame packing
0001 ~ 0101
Reserved for future use
0110
Top-and-Bottom
0111
Reserved for future use.
1000
Side-by-Side (Half)
1001 ~ 1111
Reserved for future use
For Side-by-Side (Half), the original left and right pictures are sub-sampled to half
resolution on the horizontal axis. Sub-sampled pictures are arranged in Side-by-Side
layout. See Figure 8-5.
For Top-and-Bottom, the original full left and right pictures are sub-sampled to half
resolution on the vertical axis. Sub-sampled pictures are arranged in Top-and-Bottom
layout. See Figure 8-6.
3D_Ext_Data
[4bits] The meaning of this field depends on the 3D_Structure value.
If 3D_Structure is 1000 (Side-by-Side (Half)), the 3D_Ext_Data field is added in the HDMI
Vendor Specific InfoFrame and shall be 00XX (i.e. from 0000 to 0011, horizontal
sub-sampling). For other values, see Appendix H.
If 3D_Structure is 1001~1111, the 3D_Ext_Data field is also added and indicates
additional information about the 3D format.
If 3D_Structure is 0000~0111, the 3D_Ext_Data field shall not be present.
8.2.3.1
HDMI Video format Identification Code
In this section, HDMI video timing formats which are identified by HDMI_VIC numbers are defined.
The following video formats shown in Table 8-14 are used for 4K x 2K video signal transmission.
The meaning of each parameter in Table 8-14 is defined by Figure 8-1 and Figure 8-2.
1
In this specification the term “Top-and-Bottom” is used to describe this 3D structure; it is
equivalent to the term "Over-Under" that is often used in other literature.
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Table 8-14 HDMI_VIC for extended resolution transmission
HDMI_VIC
Description
Pixel
frequency
(MHz)
Hactive
Hblank
Hfront
Hsync
Hback
0x00
Reserved
-
-
-
-
-
-
0x01
4K x 2K
29.97, 30 Hz
297.000
296.703
3840
560
176
88
296
0x02
4K x 2K 25Hz
297.000
3840
1440
1056
88
296
0x03
4K x 2K
23.98, 24 Hz
297.000
296.703
3840
1660
1276
88
296
0x04
4K x 2K 24 Hz
(SMPTE)
297.000
4096
1404
1020
88
296
0x05..0xFF
Reserved
-
-
-
-
-
-
Description
Vfreq
(Hz)
Vactive
Vblank
Vfront
Vsync
Vback
(Continued)
HDMI_VIC
0x00
Reserved
-
-
-
-
-
-
0x01
4K x 2K
29.97, 30 Hz
30.000
29.970
2160
90
8
10
72
0x02
4K x 2K 25Hz
25.000
2160
90
8
10
72
0x03
4K x 2K
23.98, 24 Hz
24.000
23.976
2160
90
8
10
72
0x04
4K x 2K 24 Hz
(SMPTE)
24.000
2160
90
8
10
72
0x05..0xFF
Reserved
-
-
-
-
-
-
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Hblank
Version 1.4b
Hactive
Vblank
Vfreq
Vactive
Figure 8-1 extended resolution format
Hblank
Hactive
Data Enable
HSYNC
Hsync
Hfront
Hback
Data
Enable
HSYNC
VSYNC
Vfront
Vsync
Vback
Figure 8-2 extended resolution format (detailed timing)
8.2.3.2
3D video format structure
The 3D video format is indicated using the VIC (Video Identification Code) in the AVI InfoFrame
(indicating the video format of one of the 2D pictures, as defined in CEA-861-D or Table 8-4) in
conjunction with the 3D_Structure field in the HDMI Vendor Specific InfoFrame (indicating the 3D
structure).
Frame packing is one of the HDMI 3D video format structures indicated by the 3D_Structure field
and is composed of two stereoscopic pictures: Left and Right, defined as shown in Figure 8-3.
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Hblank(pixel)
2D video
-
Hactive(pixel)
Vblank(line)
2D horizontal total pixel
1/ Vfreq(sec)
2D vertical
total line
Vact_space(line)
Vactive(line)
Vactive(line)
Vblank(line)
Hactive(pixel)
Vactive(line)
1/ Vfreq(sec)
Hblank(pixel)
Version 1.4b
3D horizontal total pixel is equal to 2D horizontal total pixel.
3D vertical total line is x2 of 2D vertical total line.
3D pixel clock frequency is x2 of 2D pixel clock frequency
This structure can be applied only for progressive video format.
Active video
L
3D vertical
total line
Active space
Active video
R
3D horizontal total pixel
3D video
Vact_space = Vblank
Figure 8-3 3D structure (Frame packing for progressive format)
In this figure, the area inserted between the two Active video regions is designated as “Active
space”. This Active space area shall be encoded in the same manner as the adjoining Active video
regions. During the Active space, an HDMI Source shall transmit a constant pixel value. HDMI
Sinks shall ignore all data received during the Active space regardless of the value.
Frame packing may also be applied for interlaced video timing formats. Figure 8-4 shows the 3D
structure for interlaced video timing formats.
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Vertical blanking signal
2D_V detail
Hblank(pixel)
Hactive(pixel)
3D_V detail
Hblank(pixel)
1/ Vfreq(sec)
Vblank – 0.5 (line)
Vblank – 0.5 (line)
odd
Vactive(line)
Vblank + 0.5 (line)
Active video
Vactive(line)
2D vertical
total line
Vact_space1 (line)
Vactive(line)
Vact_space2 (line)
2D video
2D_V detail
3D_V detail
Vactive(line)
Vact_space1 (line)
Vfront
Vsync
Active space
Active video
Vactive(line)
V sync signal
Vfront
Vsync
R odd
3D vertical
total line
Active space
Active video
2 / Vfreq (sec)
2D horizontal total pixel
L odd
Active space
Active video
even
Vactive(line)
Vertical blanking signal
Hactive(pixel)
L even
R even
3D horizontal total pixel
3D video
Vblank – 0.5
Vblank – 0.5
Vback
Vback
- 3D horizontal total pixel is equal to 2D horizontal total pixel.
- 3D vertical total line is x2 of 2D vertical total line.
- 3D pixel clock frequency is x2 of 2D pixel clock frequency.
- 3D Vsync pulse is inserted per frame. (2D Vsync pulse is inserted per field)
- Vactive is number of active lines per field.
- This structure can be applied only for interlaced video format
Vact_space1
Vact_space2
= Vblank + 0.5
= Vblank – 0.5
(note) This structure is applied only for interlaced formats, so the value of
Vblank has a fraction of 0.5 line to indicate that the blanking period of
1st field and 2nd field is different.
However, in the case of VIC=39, the blanking period of both fields has
the same value so that the items shown as
"(Vblank – 0.5)", "(Vblank + 0.5)" and "Vact_space1", "Vact_space2" in
this figure all have the same integer value 85.
Figure 8-4 3D structure (Frame packing for interlaced format)
Side-by-Side (Half) is one of the HDMI 3D video format structures indicated by the 3D_Structure
field and is composed of two stereoscopic pictures: Left and Right which are sub-sampled to half
resolution on the horizontal axis, and defined as shown in Figure 8-5.
Hblank(pixel)
Vblank(line)
Hactive(pixel)
L
Hactive / 2
2D horizontal total pixel
2D video
-
Vactive(line)
2D vertical
total line
1/ Vfreq(sec)
Vblank(line)
Hactive(pixel)
Vactive(line)
1/ Vfreq(sec)
Hblank(pixel)
R
3D vertical
total line
Hactive / 2
3D horizontal total pixel
3D horizontal total pixel is equal to 2D horizontal total pixel.
3D vertical total line is equal to 2D vertical total line.
3D pixel clock frequency is equal to 2D pixel clock frequency.
For interlaced formats, Vactive is number of active lines per field
3D video
Figure 8-5 3D structure (Side-by-Side (Half))
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Top-and-Bottom is one of the HDMI 3D video format structures indicated by the 3D_Structure field
and is composed of two stereoscopic pictures: Left and Right, which are subsampled to half
resolution on the vertical axis, and defined as shown in Figure 8-6.
Hblank(pixel)
Hblank(pixel)
2D horizontal total pixel
3D vertical
total line
L
Vactive / 2
R
Vactive / 2
3D horizontal total pixel
2D video
-
Hactive(pixel)
Vblank(line)
Vactive(line)
1/ Vfreq(sec)
2D vertical
total line
Vactive(line)
1/ Vfreq(sec)
Vblank(line)
Hactive(pixel)
3D video
3D horizontal total pixel is equal to 2D horizontal total pixel.
3D vertical total line is equal to 2D vertical total line.
3D pixel clock frequency is equal to 2D pixel clock frequency.
For interlaced formats, Vactive is number of active lines per field
Figure 8-6 3D structure (Top-and-Bottom)
Table 8-15 shows the detailed timing of the 3D video formats for some VICs. Figure 8-7 shows the
meaning of several parameters in Table 8-15.
If an HDMI Source has the 3D Video Format capability, then the HDMI Source shall support
transmission for at least one of the formats listed in Table 8-15.
Table 8-15 3D transmission video formats
3D _Structure
VIC
description
Hactive
Hblank
0000
(Frame packing)
32
4
19
5
20
32
4
19
1080p, 23.98 / 24Hz
720p, 59.94 / 60Hz
720p, 50Hz
1080i, 59.94 / 60 Hz
1080i, 50 Hz
1080p, 23.98 / 24Hz
720p, 59.94 / 60Hz
720p, 50Hz
1920
1280
1280
1920
1920
1920
1280
1280
830
370
700
280
720
830
370
700
1000
(Side-by-Side (Half))
0110
(Top-and-Bottom)
Hfront
638
110
440
88
528
638
110
440
Hsync
44
40
40
44
44
44
40
40
Hback
148
220
220
148
148
148
220
220
(Continued)
Vactive
Vact_
space
Vblank
1080
720
720
540
45
30
30
n.a.
540
n.a.
1080
720
720
n.a.
n.a.
n.a.
45
30
30
22(field1)
23(field2)
22(field1)
23(field2)
45
30
30
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Vfront
4
5
5
2
2.5
2
2.5
4
5
5
Vsync
5
5
5
5
5
5
5
5
5
5
Vback
36
20
20
15
15.5
15
15.5
36
20
20
Pixel freq
(MHz)
V freq
(Hz)
148.35 / 148.50
148.35 / 148.50
148.50
74.176 / 74.25
23.976 / 24.000
59.940 / 60.000
50.000
59.940 / 60.000
74.25
50.000
74.176 / 74.25
74.176 / 74.25
74.25
23.976 / 24.000
59.940 / 60.000
50.000
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Hblank
Version 1.4b
Hactive
Data Enable
HSYNC
Hsync
Hfront
Hback
Data
Enable
HSYNC
VSYNC
Vfront
Vsync
Vback
Figure 8-7 Detailed timing parameters
Note that the Frame packing 3D structure, the Side-by-Side (Half) 3D structure, and the
Top-and-Bottom 3D structure may also be used optionally with VIC codes other than those
mentioned in Table 8-15.
Primary 3D Video Format Timings
1280x720p @ 59.94/60Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1280x720p @ 50Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1280x720p @ 23.98/24Hz
(Frame Packing)
1280x720p @ 29.97/30Hz
(Frame Packing)
1920x1080i @ 59.94/60Hz
(Frame Packing, Side-by-Side(Half))
1920x1080i @ 50Hz
(Frame Packing, Side-by-Side(Half))
1920x1080p @ 23.98/24Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080p @ 29.97/30Hz
(Frame Packing, Top-and-Bottom)
1920x1080p @ 59.94/60Hz
(Top-and-Bottom)
1920x1080p @ 50Hz
(Top-and-Bottom)
Secondary 3D Video Format Timings
640x480p @ 59.94/60Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080i @ 59.94/60Hz
(Top-and-Bottom)
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720x480p @ 59.94/60Hz
720(1440)x480i @ 59.94/60Hz (Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080i @ 50Hz
(Top-and-Bottom)
720x576p @ 50Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720(1440)x576i @ 50Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720(1440)x240p @ 59.94/60Hz(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
2880x480i @ 59.94/60Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
2880x240p @ 59.94/60Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1440x480p @ 59.94/60Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080p @ 59.94/60Hz
(Frame Packing, Side-by-Side(Half))
720(1440)x288p @ 50Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
2880x576i @ 50Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
2880x288p @ 50Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1440x576p @ 50Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080p @ 50Hz
(Frame Packing, Side-by-Side(Half))
1920x1080p @ 25Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080p @ 29.97/30Hz
(Side-by-Side(Half))
2880x480p @ 59.94/60Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
2880x576p @ 50Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080i (1250 total) @ 50Hz (Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720(1440)x480i@ 119.88/120Hz (Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720x480p @ 119.88/120Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080i @ 119.88/120Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1280x720p @ 119.88/120Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720(1440)x480i@ 239.76/240Hz (Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720x480p @ 239.76/240Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720(1440)x576i @ 100Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720x576p @ 100Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1920x1080i @ 100Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1280x720p @ 100Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720(1440)x576i @ 200Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
720x576p @ 200Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1280x720p @ 23.98/24Hz
(Side-by-Side(Half), Top-and-Bottom)
1280x720p @ 25Hz
(Frame Packing, Side-by-Side(Half), Top-and-Bottom)
1280x720p @ 29.97/30Hz
(Side-by-Side(Half), Top-and-Bottom)
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1920x1080p @ 119.88/120Hz (Side-by-Side(Half), Top-and-Bottom)
1920x1080p @ 100Hz
Version 1.4b
(Side-by-Side(Half), Top-and-Bottom)
An HDMI Source shall not send any 3D video format to a Sink that does not indicate support for
that format.
Additional 3D video formats may be specified in a future version. See Appendix H.
Note: The HDMI_VIC field in the HDMI Vendor Specific InfoFrame is not used for 3D transmission.
8.3
E-EDID Data Structure
All Sinks shall contain a CEA-861-D compliant E-EDID data structure accessible through the DDC.
A Source shall read the EDID 1.3 and first CEA Extension to determine the capabilities supported
by the Sink. Additional extensions may be read to discover additional capabilities. The Source is
responsible for any format conversions that may be necessary to supply audio and video in an
understandable form to the Sink. However, it is permitted for a Source to transmit Basic Audio (see
Section 7.3) to a Sink that does not indicate support for Basic Audio.
The Source shall not transmit at TMDS clock rates higher than the maximum rate supported by the
Sink, as determined by video format and Deep Color mode support indications but limited by the
Max_TMDS_Clock field of the HDMI VSDB.
The overall structure of the E-EDID in the Sink shall conform to the E-EDID structure defined in the
VESA E-EDID Standard Release A, Revision 1, but shall also meet the additional requirements
specified herein.
The first 128 bytes of the E-EDID shall contain an EDID 1.3 structure. The contents of this
structure shall also meet the requirements of CEA-861-D.
8.3.1
CEA Extension
The first E-EDID Extension (which is not a Block Map) shall contain a CEA Extension version 3,
defined in CEA-861-D section 7.5. Additional CEA Extensions may also be present. The E-EDID
shall not contain a CEA Extension version 1 or version 2.
CEA Extension version 3 details are described in CEA-861-D Section 7.5.
Further details on the requirements of the data structures in the E-EDID and implementation
examples are given in CEA-861-D.
8.3.2
HDMI Vendor-Specific Data Block (HDMI VSDB)
The first CEA Extension shall include an HDMI Vendor Specific Data Block (HDMI VSDB) shown
in Table 8-16.This is a CEA-861-D Vendor Specific Data Block (see CEA-861-D section 7.5.4 for
details) containing a 24-bit IEEE Registration Identifier of 0x000C03, a value belonging to HDMI
Licensing, LLC.
Sinks shall contain an HDMI VSDB minimally containing a 2-byte Source Physical Address field
following the 24-bit identifier. An HDMI VSDB may have zero or more extension fields as shown
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in Table 8-16. The minimum value of N (length) is 5 and the maximum value of N is 31. A Sink that
supports any function indicated by an extension field shall use an HDMI VSDB with a length
sufficient to cover all supported fields.
The Source shall have the ability to handle an HDMI VSDB of any length. In future specifications,
new fields may be defined. These additional fields will be defined such that a zero value indicates
the same characteristics as is indicated if the field was not present. Sources should use the length
field to determine which extension fields are present, and shall process the HDMI VSDB with no
regard to non-zero values in fields defined as Reserved in this specification.
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Table 8-16 HDMI-LLC Vendor-Specific Data Block (HDMI VSDB)
Byte #
0
7
6
5
4
3
2
Vendor-specific tag code (=3)
1
1
0
Rsvd
(0)
Rsvd
(0)
DVI_
Dual
CNC2
CNC1
CNC0
Rsvd
(0)
Rsvd
(0)
Length (=N)
24-bit IEEE Registration Identifier (0x000C03)
(least significant byte first)
2
3
4
A
B
5
C
D
6
Supports
_AI
DC_
48bit
DC_
36bit
DC_
Y444
Latency_
Fields_
Present
I_Latency_
Fields_
Present
HDMI_V
ideo_pre
sent
Rsvd
(0)
CNC3
(9)
Video_Latency
(10)
Audio_Latency
(11)
Interlaced_Video_Latency
(12)
Interlaced_Audio_Latency
(13)
(14)
(15)
extension
fields
Max_TMDS_Clock
7
8
DC_
30bit
3D_pres
ent
3D_Multi_present
Rsvd
(0)
Image_Size
HDMI_VIC_LEN
HDMI_3D_LEN
(if HDMI_VIC_LEN > 0)
HDMI_VIC_1
…
…
HDMI_VIC_M
(if 3D_Multi_present = 01 or 10)
3D_Structure_ALL_15…8
3D_Structure_ALL_7…0
(if 3D_Multi_present = 10)
3D_MASK_15…8
3D_MASK_7…0
2D_VIC_order_1
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3D_Detail_1 ***
Version 1.4b
Reserved(0) ***
…
2D_VIC_order_L
( )*…N
3D_Structure_L
Reserved (0)**
* The position of these bytes will depend upon the values of Latency_Fields_Present,
I_Latency_Fields_Present and HDMI_Video_present.
** No additional bytes are necessary but if present, they shall be zero.
*** The bytes with 3D_Detail_X and Reserved(0) are present only for some values of 3D_Structure_X. See
below for details
Length
[5 bits] Total length of data block, not including this byte. Shall be 5
(encompassing fields only up to C and D fields) or greater, to encompass additional fields.
A, B, C, D [4 bits each] Components of Source Physical Address (A.B.C.D). See Section
8.7.
Supports_AI
[1 bit] Set to 1 if the Sink supports at least one function that uses
information carried by the ACP, ISRC1, or ISRC2 packets. If Supports_AI is set (=1), then
the Sink shall accept and process any ACP, ISRC1 or ISRC2 packet with no regard to
non-zero values in fields defined as Reserved in this specification. If the Sink does not
support ACP, ISRC1 or ISRC2 packets, Supports_AI shall be clear (=0).
DC_48bit [1 bit] Set if Sink supports 48 bits/pixel (16 bits/color).
DC_36bit [1 bit] Set if Sink supports 36 bits/pixel (12 bits/color).
DC_30bit [1 bit] Set if Sink supports 30 bits/pixel (10 bits/color).
DC_Y444 [1 bit] Set if Sink supports YCBCR 4:4:4 in Deep Color modes.
The three DC_XXbit bits above only indicate support for RGB 4:4:4 at that pixel size. Support for
YCBCR 4:4:4 in Deep Color modes is indicated with the DC_Y444 bit. If DC_Y444 is set, then
YCBCR 4:4:4 is supported for all modes indicated by the DC_XXbit flags. This provides the Sink the
flexibility of supporting YCBCR formats for the standard color-depth (24-bits/pixel) while only
supporting RGB for Deep Color modes.
DVI_Dual [1 bit] Set if Sink supports DVI dual-link operation.
Max_TMDS_Clock [1 byte] Indicates the maximum TMDS clock rate supported. Max rate
= Max_TMDS_Clock * 5MHz. This field shall be set correctly and non-zero if the Sink
supports TMDS clock frequencies above 165MHz or supports any Deep Color mode or
supports DVI dual-link. A value of zero means that no clock rate is indicated.
The Max_TMDS_Clock field may be set by the Sink at a level below the TMDS clock rate
corresponding to the maximum pixel clock rate at the maximum color depth. This allows the Sink
to support higher color depths at lower resolutions than it can support at higher resolutions.
Latency_Fields_Present
[1 bit] If set (=1) then the Video_Latency and Audio_Latency
fields are present. If clear (=0) then these fields are not present in the HDMI VSDB. See
section 8.9 for more detail.
I_Latency_Fields_Present
[1 bit] If set (=1) then the latency fields total four bytes, two
for video and audio latency information when progressive video formats are received and
two for latency information when interlaced video formats are received. If clear (=0) then
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only two bytes are present, indicating the video and audio latency when any video format
is received. I_Latency_Fields_Present shall be zero if Latency_Fields_Present is zero.
See section 8.9 for more detail.
HDMI_Video_present
[1bit] If set (=1) then additional video format capabilities are
described by using the fields starting after the Latency area. This consists of 4 parts with
the order described below:
- 1 byte containing the 3D_present flag and other flags
- 1 byte with length fields HDMI_VIC_LEN and HDMI_3D_LEN
- zero or more bytes for information about HDMI_VIC formats supported
(length of this field is indicated by HDMI_VIC_LEN).
- zero or more bytes for information about 3D formats supported
(length of this field is indicated by HDMI_3D_LEN)
which are optionally composed of 3D_Structure_ALL_15...0,
3D_MASK_15...0, 2D_VIC_order_X, 3D_Structure_X and 3D_Detail_X field.
CNC3…0 [4bits] Each of these bits indicates support for a particular Content Type. See
Table 8-17. When the Source indicates that it is sending Graphics, Photo, Cinema or
Game content, the Sink is expected to use the corresponding processing specified in
Table 8-17.
Table 8-17 Content Type
CNC3-0
Content Type
CNC0
Graphics
(text)
CNC1
Photo
CNC2
Cinema
CNC3
Game
Description
Set (=1) if the sink device can pass the pixel data without filtering and
analog reconstruction because adjacent pixels are completely
independent and should not interact.
Set (=1) if the sink device has specific processing for still pictures.
Set (=1) if the sink device has specific processing for cinema content, e.g.
film tone reproduction.
Set (=1) if the sink device has a specific processing mode with low Audio
and Video latency.
Video_Latency
[1 byte] Indicates the amount of video latency when receiving any
video format or only when receiving progressive video formats; if
I_Latency_Fields_Present flag == 1 then this field only indicates the latency while
receiving progressive video formats, otherwise this field indicates the latency when
receiving any video format. Value is number of (milliseconds / 2) + 1 with a maximum
allowed value of 251 (indicating 500 millisecond duration). A value of 0 indicates that the
field is not valid or that the latency is unknown. A value of 255 indicates that no video is
supported in this device or downstream. See section 8.9 for more detail.
Audio_Latency
[1 byte] Indicates the amount of audio latency when receiving any
video format or only when receiving progressive video formats; if
I_Latency_Fields_Present flag == 1 then this field only indicates the latency while
receiving progressive video formats, otherwise this field indicates the latency when
receiving any video format. Value is number of (milliseconds / 2) + 1 with a maximum
allowed value of 251 (indicating 500 millisecond duration). A value of 0 indicates that the
field is not valid or that the latency is unknown. A value of 255 indicates that no audio is
supported in this device or downstream. See section 8.9 for more detail.
Interlaced_Video_Latency
[1 byte] This field is only present if
I_Latency_Fields_Present flag == 1. If present, the field indicates the amount of video
latency when receiving an interlaced video format. Format is identical to Video_Latency
field. See section 8.9 for more detail.
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Interlaced_Audio_Latency
[1 byte] This field is only present if
I_Latency_Fields_Present flag == 1. If present, the field indicates the amount of audio
latency when receiving an interlaced video format. Format is identical to Audio_Latency
field. See section 8.9 for more detail.
3D_present
[1bit] This bit indicates 3D support by the HDMI Sink, including the
mandatory formats. If set (=1), an HDMI Sink supports the 3D video formats that are
mandatory formats, plus any additional formats indicated by combining the indications in
both:
- 3D_Structure_ALL_15…0 (if 3D_Multi_present = 01), or
3D_Structure_ALL_15…0 and 3D_MASK_15…0 (if 3D_Multi_present = 10);
and
- 2D_VIC_order_X, 3D_Structure_X and 3D_Detail_X
(if these fields are present according to the HDMI_3D_LEN calculation).
3D_Multi_present [2bit]
If 3D_Multi_present = 00
3D_Structure_ALL_15…0 and 3D_MASK_15…0 fields are not present.
If 3D_Multi_present = 01,
3D_Structure_ALL_15…0 is present and assigns 3D formats to all of the VICs listed
in the first 16 entries in the EDID. 3D_MASK_15…0 is not present.
If 3D_Multi_present = 10,
3D_Structure_ALL_15…0 and 3D_MASK_15…0 are present and assign 3D formats to
some of the VICs listed in the first 16 entries in the EDID.
If 3D_Multi_present = 11
Reserved for future use.
Note: 3D_Structure_ALL_15…0 and 3D_MASK_15…0 are not present.
Image_Size
[2bit] indicates additional properties of the values in the Image Size
area in the EDID. (Image Size area means ‘Max Horizontal Image Size’ and ‘Max Vertical
Image Size’ fields that are assigned on address 0x15 and 0x16 in VESA E-EDID
specification.)
Table 8-18 Image_Size
Image_Size
[1]
Image_Size
[0]
0
0
0
1
1
0
1
1
Description
No additional information
Values in the Image Size area indicate correct aspect ratio but the sizes are
not guaranteed to be correct.
Values in the Image Size area indicate correct sizes which are rounded to the
nearest 1 centimeter (cm).
Values in the Image Size area indicate correct sizes in divided by 5 format,
which are rounded to the nearest 5 centimeter (cm).
This mode is used only if the real horizontal size is larger than 255cm.
(Example; in the case of 150 inch 16:9 panel, the real horizontal size is
332.1cm and the value 0x42 is applied in the ‘Max Horizontal Image Size’
area. (332.1 div 5 = 66.4 66 = 0x42)
And the value 0x25 is applied in the ‘Max Vertical Image Size’ area (186.8 div
5 = 37.36 37 = 0x25))
HDMI_VIC_LEN
HDMI_3D_LEN
[5bits] indicates the total length of following 3D video format
capabilities including 3D_Structure_ALL_15...0, 3D_MASK_15...0, 2D_VIC_order_X,
3D_Structure_X and 3D_Detail_X fields.
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[3bits] indicates the total length from HDMI_VIC_1 to HDMI_VIC_M.
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HDMI_VIC_X
[1 byte] X means the index value from 1 to M. This field indicates the
video formats which are supported by the Sink. The HDMI_VIC_X values are defined in
section 8.2.3.1.
3D_Structure_ALL_15…0
[2 bytes] For each bit in this field which is set (=1), an HDMI
Sink supports the corresponding 3D_Structure according to Table 8-19 for all of the VICs
listed in the first 16 entries in the EDID. By using this field, the 3D capabilities of an HDMI
Sink can be concisely described. For other values, see Appendix H.
Table 8-19 3D_Structure_ALL
Bit
Meaning
3D_Structure_ALL_0
Sink supports “Frame packing” 3D formats.
3D_Structure_ALL_1…5
Reserved (0)
3D_Structure_ALL_6
Sink supports “Top-and-Bottom” 3D formats
3D_Structure_ALL_7
Reserved (0)
3D_Structure_ALL_8
Sink supports “Side-by-Side(Half) with horizontal sub-sampling” 3D formats
3D_Structure_ALL_9…15
Reserved (0)
3D_MASK_15…0 [2 bytes] Where a bit is set (=1), for the corresponding VIC within the
first 16 entries in the EDID, the Sink indicates 3D support as designated by the
3D_Structure_ALL_15…0 field.
Where a bit is not set (=0), for the corresponding VIC, the Sink does not indicate 3D
support using this field (whereas it may indicate 3D support by the 2D_VIC_order_X,
3D_Structure_X and 3D_Detail_X fields, if present).
3D_MASK_0
=
first VIC
3D_MASK_1
=
second VIC
:
:
:
3D_MASK_15
=
16th VIC
Note: The Sink shall not set the corresponding bit to 1 for cases in which the
corresponding 3D video signal exceeds the clock rate at the Max_TMDS_Clock * 5MHz.
2D_VIC_order_X [4bits] X means the index value from 1 to L. The value of this field is a
pointer to a particular VIC in the EDID based on the order in which the VICs are stored in
the EDID. The value 0000 corresponds to the first VIC in the EDID, and the remaining
values point to the rest of the first 15 VIC entries in the EDID in corresponding order.
2D_VIC_order_X = 0000 corresponds to the first VIC in the EDID
2D_VIC_order_X = 0001 corresponds to the second VIC in the EDID
:
:
:
2D_VIC_order_X = 1111 corresponds to the 16th VIC in the EDID
3D_Structure_X
[4bits] X means the index value from 1 to L. This field indicates the 3D
capability for the corresponding VIC code indicated by 2D_VIC_order_X. The value is
defined in Table 8-13.
3D_Detail_X
[4bits] X means the index value from 1 to L. This field indicates
additional detailed information for the related 3D_Structure_X field.
If 3D_Structure_X is 0000~0111, this field and also the 4-bit reserved field in the same
byte, shall not be present, so the X-th entry consists only of 2D_VIC_order_X and
3D_Structure_X (1 byte).
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If 3D_Structure_X is 1000~1111 (including Side-by-Side (Half)), this field and also the
4-bit reserved field in the same byte, shall be present, so the X-th entry consists of
2D_VIC_order_X, 3D_Structure_X and 3D_Detail_X (2 bytes).
If 3D_Structure_X is 1000, the value of this field 3D_Detail_X shall be 0001 (horizontal
sub-sampling). For other values, see Appendix H.
If 3D_present is set (=1), an HDMI Sink shall support 3D video formats per the following
requirements.
・ An HDMI Sink which supports at least one 59.94 / 60Hz 2D video format shall support
all of;
1920x1080p @ 23.98 / 24Hz
Frame packing
1280x720p @ 59.94 / 60Hz
Frame packing
1920x1080i @ 59.94 / 60Hz
Side-by-Side (Half)
1920x1080p @ 23.98 / 24Hz
Top-and-Bottom
1280x720p @ 59.94 / 60Hz
Top-and-Bottom
・ An HDMI Sink which supports at least one 50Hz 2D video format shall support all of;
1920x1080p @ 23.98 / 24Hz
Frame packing
1280x720p @ 50Hz
Frame packing
1920x1080i @ 50Hz
Side-by-Side (Half)
1920x1080p @ 23.98 / 24Hz
Top-and-Bottom
1280x720p @ 50Hz
Top-and-Bottom
Setting 3D_present (=1) in the HDMI VSDB indicates support for the mandatory formats
above and no further 3D video indication in the HDMI VSDB is required for the mandatory
formats.
Additional 3D video formats may be specified in a future version. See Appendix H.
8.3.3
Colorimetry Data Block
The Colorimetry Data Block indicates support of specific extended colorimetry standards and
gamut related, as yet undefined, metadata. Details regarding the contents of the Colorimetry Data
Block are provided in Table 8-20, Table 8-21 and Table 8-22.
Byte 3 is allocated for Colorimetry data. The flags for bits 0 through 4 are defined for colorimetry
based upon the IEC 61966-2 series of standards. The definitions of the colorimetry flags are
shown in Table 8-21. Setting a colorimetry flag to one shall indicate that the sink is capable of
displaying pictures encoded in that colorimetry.
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Table 8-20 Colorimetry Data Block
Bits
Byte #
1
2
3
4
7
6
5
Tag Code = 0x07
F37=0
F47=0
F36=0
F46=0
F35=0
F45=0
4
3
2
1
0
Length of following data block (in bytes) = 0x03
Extended Tag Code =0x05
AdobeRGB AdobeYCC601 sYCC601 xvYCC709 xvYCC601
F44=0
MD3
MD2
MD1
MD0
Table 8-21 Data Byte 3 Colorimetry Support flags
Flag
Colorimetry
xvYCC601
xvYCC709
sYCC601
AdobeYCC601
AdobeRGB
Standard Definition Colorimetry based on IEC 61966-2-4
High Definition Colorimetry based on IEC 61966-2-4
Colorimetry based on IEC 61966-2-1/Amendment 1
Colorimetry based on IEC 61966-2-5, Annex A
Colorimetry based on IEC 61966-2-5
Table 8-22 Data Byte 4 Colorimetry Metadata Support flags
Flag
MD0
MD1
MD2
MD3
8.3.4
Metadata
See Appendix E
Future metadata profile
Future metadata profile
Future metadata profile
Video Capability Data Block (VCDB)
The Video Capability Data Block (VCDB) allows a display to declare default, fixed, or InfoFrame
controlled quantization range (see Table 8-23).
NOTE—The VCDB payload currently only contains a single byte in addition to the Extended Tag
Code, while future versions may contain additional bytes. The source should ignore such
additional bytes (when present) and continue to parse the single byte as defined in Table 8-23.
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Table 8-23 Video Capability Data Block (VCDB)
Bits
Byte #
7
1
6
5
Tag Code = 0x07
3
2
1
0
Length of following data block (in bytes) = 0x02
2
3
4
Extended Tag Code =0x00
QY
QS
S_PT1
S_PT0
S_IT1
S_IT0
S_CE1
S_CE0
Table 8-24 Quantization Range (Applies to YCC only)
QY
0
1
Quantization Range (Applies to YCC only)
No Data
Selectable (via AVI YQ)
QS
Quantization Range (Applies to RGB only).
See CEA-861-D table 43 for details.
S_PT0…S_PT1
PT Overscan/underscan behavior (Applies to the preferred video
format).
See CEA-861-D table 43 for details.
S_IT0…S_IT1
IT Overscan/underscan behavior (Applies to IT video formats).
See CEA-861-D table 43 for details.
S_CE0…S_CE1
CE Overscan/underscan behavior (Applies to CE video formats).
See CEA-861-D table 43 for details.
8.3.5
DVI/HDMI Device Discrimination
In order to determine if a sink is an HDMI device, an HDMI Source shall check the E-EDID for the
presence of an HDMI Vendor Specific Data Block within the first CEA Extension. Any device with
an HDMI VSDB of any valid length, containing the IEEE Registration Identifier of 0x000C03, shall
be treated as an HDMI device.
Any device with an E-EDID that does not contain a CEA Extension or does not contain an HDMI
VSDB of any valid length shall be treated by the Source as a DVI device (see Appendix C).
8.3.6
Audio and Video Details
Sink audio characteristics and support are indicated in a series of Short Audio Descriptors located
in the CEA Extension’s Data Block collection. This data includes a list of audio encodings
supported by the Sink and parameters associated with each of those encodings, such as number
of channels supported for that format. A Speaker Allocation Descriptor may also be included in the
Data Block collection and is required for Sinks supporting multi-channel L-PCM or multi-channel
One Bit Audio. See section 7.5.2 and 7.5.3 of CEA-861-D for details.
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A Sink may indicate support for YCBCR pixel encodings. To indicate support, bits 4 and 5 of byte 3
of the CEA Extension shall both be set to one (see Table 27 of CEA-861-D). To indicate no
support, bits 4 and 5 shall both be zero.
With the exception of 640x480p video format, if a Sink is required to support a particular video
format, video format timing, or pixel encoding, then the Sink shall indicate support for that video
format, video format timing or pixel encoding in the E-EDID. Explicit indication of 640x480p is
optional but is not required because all Sinks are required to support that video format.
To indicate support for any video format in section 6.3, an HDMI Sink shall use a Short Video
Descriptor (SVD) containing the Video Code for that format and may also use a Detailed Timing
Descriptor (DTD).
If the Sink supports extended colorimetries (those beyond the default standard- and high-definition
colorimetries) or supports the reception of gamut-related metadata, the Sink shall use a
Colorimetry Data Block to indicate support for these colorimetries and metadata. See section
6.7.2.4 for more details.
8.4
Enhanced DDC
Enhanced DDC described in this section is defined in VESA “ENHANCED DISPLAY DATA
CHANNEL STANDARD Version 1 (September 2, 1999)”. All Sinks are required to support these
enhanced DDC features. If a Sink’s E-EDID structure is longer than 256 bytes, it shall support the
segment pointer.
8.4.1
Timing
Data is synchronized with the SCL signal and timing shall comply with the Standard Mode of the
I2C specification (100kHz maximum clock rate).
I2C Bus is a standard two-wire (clock and data) serial data bus protocol. Refer to the I2C
specification for details.
Note that an HDMI Sink may hold off the DDC transaction by stretching the SCL line during the
SCL-low period following the Acknowledge bit as permitted by the I2C specification. All HDMI
Sources shall delay the DDC transaction while the SCL line is being held low.
8.4.2
Data Transfer Protocols
The Source shall use I2C commands to read information from a Sink’s E-EDID with a slave
address.
In Enhanced DDC, a segment pointer is used to allow addressing of the E-EDID outside of the
normal 256-byte limit of the 0xA0/0xA1 address. The Enhanced DDC protocol sets the segment
pointer before the remainder of the DDC command.
8.4.3
Segment pointer
Enhanced DDC allows access of up to 32 Kbytes of data. This is accomplished using a
combination of the 0xA0/0xA1 address pair and a segment pointer. For each value of the segment
pointer, 256 bytes of data are available at the 0xA0/0xA1 address pair. An unspecified segment
pointer references the same data as when the segment pointer is zero.
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Each successive value of the segment pointer allows access to the next two blocks of E-EDID
(128 bytes each). The value of the segment pointer register cannot be read since it is reset at the
completion of each command.
8.4.4
Enhanced DDC Sink
The Sink shall be Enhanced DDC read compliant.
The Sink shall be capable of responding with EDID 1.3 data and up to 255 extension blocks, each
128 bytes long (up to 32K bytes total E-EDID memory) whenever the Hot Plug Detect signal is
asserted.
The Sink should be capable of providing E-EDID information over the Enhanced DDC channel
whenever the +5V Power signal is provided. This should be available within 20msec after the +5V
Power signal is provided.
8.4.5
Enhanced DDC Source
The Source shall use Enhanced DDC protocols.
The Source shall be capable of reading EDID 1.3 data at DDC address 0xA0.
The Source reads Enhanced EDID extensions data at DDC address 0xA0 using segment pointer
0x60.
8.5
Hot Plug Detect Signal
An HDMI Sink shall not assert high voltage level on its Hot Plug Detect pin when the E-EDID is not
available for reading. This requirement shall be fulfilled at all times, even if the Sink is powered-off
or in standby. The Hot Plug Detect pin may be asserted only when the +5V Power line from the
Source is detected. This will ensure that the Hot Plug Detect pin is not asserted before the Third
Make of the connector (see Section 4.1.5).
A Source may use a high voltage level Hot Plug Detect signal to initiate the reading of E-EDID
data.
A Source shall assume that any voltage within the range specified for High voltage level in Table
4-39 indicates that a Sink is connected and that E-EDID is readable. It does not indicate whether
or not the Sink is powered or whether or not the HDMI input on the Sink is selected or active.
An HDMI Sink shall indicate any change to the contents of the E-EDID by driving a low voltage
level pulse on the Hot Plug Detect pin. This pulse shall be at least 100 msec.
8.6
Consumer Electronics Control (CEC)
The CEC line is used for high-level user control of HDMI-connected devices. The mandatory
requirements for the CEC line are described in detail in Section 4.2.10, CEC Line. The optional
CEC protocol is described in Supplement 1: Consumer Electronics Control (CEC).
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8.7
Physical Address
8.7.1
Overview
Version 1.4b
In order to allow CEC to be able to address specific physical devices and control switches, all
devices shall have a physical address. This connectivity has to be worked out whenever a new
device is added to the cluster. The physical address discovery process uses only the DDC/EDID
mechanism and applies to all HDMI Sinks and Repeaters, not only to CEC-capable devices.
The CEC and DDC connections are shown in Figure 8-8.
DDC line
CEC bus
Figure 8-8 CEC and DDC line connections
The CEC line is directly connected to all nodes on the network.
After discovering their own physical address, the CEC devices transmit their physical and logical
addresses to all other devices, thus allowing any device to create a map of the network.
8.7.2
Physical Address Discovery
The physical address of each node is determined through the physical address discovery process.
This process is dynamic in that it automatically adjusts physical addresses as required as devices
are physically or electrically added or removed from the device tree.
All Sinks and Repeaters shall perform the steps of physical address discovery and propagation
even if those devices are not CEC-capable. Sources are not required to determine their own
physical address unless they are CEC-capable.
All addresses are 4 digits long allowing for a 5–device-deep hierarchy. All are identified in the form
of n.n.n.n in the following description. An example of this is given in Figure 8-10.
A Sink or a Repeater that is acting as the CEC root device will generate its own physical address:
0.0.0.0. A Source or a Repeater reads its physical address from the EDID of the connected Sink.
The CEC line may be connected to only one HDMI output so a device with multiple HDMI outputs
will read its physical address from the EDID on the CEC-connected output. Each Sink and
Repeater is responsible for generating the physical address of all Source devices connected to
that device by appending a port number onto its own physical address and placing that value in
the EDID for that port. The Source Address Field of the HDMI Vendor Specific Data Block (see
Section 8.3.2) is used for this purpose.
Note that the values shown in the figures below represent the physical addresses for the devices
themselves, not the Source physical addresses stored in the EDID within that device. In fact, for all
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devices shown, except the TV, those physical addresses are stored in the EDID of the connected
Sink. An example is shown for the TV at physical address 0.0.0.0.
DVD
not pre sent
TV
D-VHS
PVR
A/V Rece iver/
Ampli fier
STB
Figure 8-9 Typical HDMI cluster
DVD
2.1.0.0
not pre sent
1.0.0 .0
0 .0.0.0
D-VHS
2.2.0.0
PVR
2.3.1.0
A/V Rece iver/
Ampli fier
2.0.0 .0
STB
2.3.0.0
EDID
1.0.0.0
0.0.0.0
EDID
2.0.0.0
Figure 8-10 Addresses within an HDMI cluster
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8.7.3
Version 1.4b
Discovery Algorithm
The following algorithm is used to allocate the physical address of each device whenever HPD is
de-asserted or upon power-up:
Disable assertion of HPD to all source devices
If I am CEC root
Set my_address to 0.0.0.0
Else
Wait for HPD from sink
Query sink for my_address of my connection (Section 8.7.4)
The device shall retain this physical address until HPD is
removed (or the device is powered off).
End if
If device has connections for source devices then
Label all possible connections to source devices uniquely starting
from connection_label = 1 to the number of source input connections
If device has separate EDIDs for each source connection then
If my_address ends with 0 then
Set each source_physical_address to my_address with the
first 0 being replaced with connection_label.
Else (i.e. beyond the fifth layer of the tree)
Set each source_physical_address to F.F.F.F
End if
Else
Set each source_physical_address to my_address
End if
Write source_physical_address to HDMI VSDB in EDID for each source
connection
End if
Allow HPD to be asserted for source devices
8.7.4
HDMI Sink Query
A Source shall determine its physical address (my_address) by checking the HDMI Vendor
Specific Data Block (see Section 8.3.2) within the EDID. The fourth and fifth bytes of this 5 byte
structure contain the Source Physical Address (fields A, B, C, D).
8.8
ISRC Handling
A Source shall not transmit an ISRC1 or ISRC2 Packet to a Sink that does not have Supports_AI =
1.
A Source may handle an International Standard Recording Code (ISRC) and/or UPC/EAN
describing the origin or owner details for each track of content on the medium. These values may
be transmitted using the ISRC1 and ISRC2 packets.
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When fields UPC_EAN_ISRC_16 through 31 include effective data (i.e. not "reserved"), a
subsequent ISRC2 Packet shall be transmitted. In other cases, the ISRC2 packet may optionally
be transmitted.
When a subsequent ISRC2 Packet is transmitted, the ISRC_Cont field shall be set and shall be
clear otherwise.
For further description of the UPC_EAN_ISRC fields, see "DVD Specifications for Read-Only Disc”,
Part 4: AUDIO SPECIFICATIONS Version 1.0, March 1999, Annex B".
Regarding usage of the ISRC_Status field, Source shall comply with “DVD Specifications for
Read-Only Disc”, “Part 4: AUDIO SPECIFICATIONS”, Version-up Information (from 1.1 to 1.2),
Table 7.2.3.1.1-2, May 2000. Following is a summary of the relevant rules from that specification:
At the beginning of each track, at least two complete UPC_EAN_ISRC codes are transmitted
with an ISRC_Status of 0b001.
During the bulk of the track, continuous repetitions of the packet(s) are required, with an
ISRC_Status of 0b010.
Immediately before the end of each track, at least two complete UPC_EAN_ISRC codes are
transmitted with an ISRC_Status of 0b100.
Music
Tracks
Track A
Track B
CCI (Copy
Control Info)
CCI A (Repeatedly)
CCI B (Repeatedly)
ISRC
ISRC A (Repeatedly)
ISRC B (Repeatedly)
ISRC status
001
010
100
001
010
100
Starting
position
Intermediate
position
Ending
position
Starting
position
Intermediate
position
Ending
position
Figure 8-11 ISRC/CCI and ISRC Status Handling
8.9
Auto Lipsync Correction Feature
Some common home theater device configurations will render the audio in a device other than the
TV. In these configurations, the video processing latency of the TV may cause perceptible lipsync
issues to the user. These issues can be corrected by delaying the audio to compensate for the
video processing latency. The HDMI Auto Lipsync Correction feature allows a Source or Repeater
to automatically determine the necessary amount of audio delay before presentation or output of
that audio signal.
8.9.1
EDID Latency Info
HDMI Sinks and Repeaters may declare audio and video latency information in the EDID, allowing
an HDMI Source or Repeater to determine how best to maintain synchronization between the
rendered audio and video. These fields and other lipsync-related fields are in the HDMI VSDB
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(see section 8.3.2). The latency values within these fields indicate the amount of time between the
video or audio entering the HDMI input to the actual presentation to the user (on a display or
speakers), whether that presentation is performed by the device itself or by another device
downstream.
Many TVs internally compensate for their own video processing latency by adding a delay to the
audio stream that corresponds to the video latency. In this case, the EDID-indicated audio and
video latencies will be equal. This delay will typically be applied for audio sent to internal speakers
as well as audio sent to external S/PDIF (or other) audio outputs so that downstream amplifiers will
also be in-sync.
A lipsync-aware Repeater will calculate the latency fields for its upstream EDID to indicate the
overall video and audio latency from the reception by the Repeater to the eventual rendering by
the Repeater or by downstream device(s). For instance, if the Repeater is a video processor the
video data will be delayed by its internal processing before being passed downstream. In this case,
the Repeater should indicate a video latency in the upstream EDID equal to the video latency
found in the downstream device’s EDID plus the Repeater’s own internal video processing
latency.
Likewise, if the Repeater is an audio amplifier which passes video through unmodified but which
renders (amplifies) the audio directly (not passing it downstream), then the upstream audio latency
will be equal to the Repeater’s audio processing latency (only). If this amplifier adds an audio
delay sufficient to compensate for the video latency of the downstream device, then the upstream
audio and video latencies will be equal, whether that Repeater forwards the audio downstream or
renders the audio directly.
8.9.1.1 Supporting a Range of Latency Values
If the video latency of a device differs significantly depending upon the video format or other factor,
it is recommended that the video latency field indicate a latency that is between the extremes but
skewed toward the longer latency. An audio/video mismatch is more perceptible if the audio leads
the video than if the video leads the audio by a similar amount. Because of this effect, indicating a
value that is closer to the maximum video delay may result in better overall user experience. For
example, a value of roughly (2 * max_latency + min_latency)/3 may be used. The same is true for
the audio latency but in this case, the indicated value should be skewed towards the minimum
latency. For example, a value of roughly (max_latency + 2*min_latency)/3 may be used.
If the optimum indication for the video latency for interlaced video formats is significantly different
than the optimum indication of latency for progressive formats, then the I_Latency_Fields_Present
flag should be set, allowing the EDID to indicate separate latencies for these two categories of
video formats. This approach may be used anytime but it is recommended in case the difference
between the two latencies is more than roughly 30 msecs.
8.9.2
Compensation
A lipsync-aware Source or Repeater may delay the audio to compensate for the video latency of
the downstream device(s), by an amount equal to the video_latency minus the audio_latency of
the downstream (or rendering) devices.
It may not be possible to determine the audio latency of non-HDMI audio outputs (e.g. S/PDIF or
analog outputs). For uncompressed audio formats, typically the value will be close to zero and so
the device can simply delay the audio by the amount of video latency in the downstream EDID. For
compressed audio formats, the device may assume that the audio latency is near the standard
decompression latency specified in the relevant IEC61937-x standard or in the codec vendor’s
documentation.
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It is expected that an audio delay capability of 100msecs will support full compensation for almost
all of the TV and video processor products on the market today.
If transmitting a progressive video format, the Video_Latency and Audio_Latency fields are used
for this calculation. If transmitting an interlaced video format, either these same fields are used or,
if I_Latency_Fields_Present == 1, then the Interlaced_Video_Latency and
Interlaced_Audio_Latency fields are used.
8.9.3
Supporting Dynamic Latency Changes
A future version of the HDMI Spec will define a mechanism for Sinks to dynamically modify their
latency information.
8.9.4
Separate Audio and Video Paths
If the Source or Repeater splits the audio and video stream for transmission to two separate
outputs, the device should calculate the required audio delay for the audio path by subtracting the
audio latency in the audio path’s EDID from the video latency in the video path’s EDID.
A Source may use the no-video value or the corresponding no-audio value (in the Audio_Latency
fields) to automatically determine whether video or audio is supported on a particular signal path.
The no-video value of the Video_Latency fields allows a Sink to declare that it does no internal
rendering of the video signal nor does it output the HDMI-received video stream on an HDMI or
non-HDMI output. This may never be true for a TV but it may be true or may change dynamically
for an audio amplifier with a video pass-through function depending upon whether any device is
connected downstream of the video output port, for example.
For a Repeater that does no video rendering, if there is no downstream video device connected to
the Repeater’s output, then the Repeater should indicate no-video. If there are downstream
device(s) connected but all of those device(s) have no-video value in the video latency field then
the Repeater should also indicate no-video.
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9
Content Protection
9.1
Recommendation
Version 1.4b
Content protection capability is recommended for all HDMI compliant devices. An HDMI compliant
Source should protect all of the protected audiovisual data. Amongst adequate copy protection
technologies that are compatible with HDMI, HDCP is available.
9.2
HDCP Implementations
HDCP implementations for HDMI shall adhere to HDCP specification Revision 1.4.
Note that if the Sink has no digital audio outputs and has typical restrictions on its analog audio
outputs (e.g. must be normal pitch) then it is recommended that Supports_AI be set. If this bit is
clear then the Sink will not be able to receive audio content from DVD-Audio and Super Audio CD.
9.3
Usage of Audio Content Protection (ACP) Packets
A Source may use the ACP Packet to convey content-related information regarding the active
audio stream.
Non-transmission of ACP Packets should be considered equivalent to transmission of an ACP
Packet with an ACP_Type field of 0. If a Sink does not receive an ACP Packet within 600msecs, it
shall revert to ACP_Type = 0 behavior.
Whenever a Source is required by other license agreements or specifications to transmit
information related to the content protection requirements of the active audio stream, ACP
Packets shall be transmitted at least once per 300msecs and an appropriate ACP_Type value
shall be set.
When transmitting ACP Packets, upon the start of a new audio stream or upon any change in the
audio stream that can be indicated by the ACP Packet, a modified, accurate ACP Packet shall be
transmitted no later than 300msec following the transmission of the affected or relevant audio
sample.
The ACP Packet transmission may occur at any time that a Data Island packet may be
transmitted.
A Source shall not transmit an ACP Packet to a Sink that does not have Supports_AI = 1.
9.3.1
Requirements for Sink
A Sink that has any type of audio output and/or audio recording function shall be capable of
receiving and appropriately handling the ACP Packet even if the Sink does not support any audio
rendering functionality.
Whenever an HDCP-capable Sink detects an ACP Packet, it shall comply with the HDCP Audio
Compliance Rules.
Whenever an HDCP-capable Sink detects an ACP Packet with an unknown ACP_Type value, it
shall comply with the HDCP Audio Compliance Rules for undefined content.
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9.3.2
Version 1.4b
Requirements for Repeater
Any content that is received by a Repeater and is accompanied by an ACP Packet shall be
accompanied with an identical ACP Packet and any concurrently received ISRC1 or ISRC2
packets when that content is transmitted to a Sink with Supports_AI = 1.
9.3.3
Application to Generic Audio
With regards to the control of copying and audio output permissions, transmission of an ACP
Packet with an ACP_Type field of 0 is equivalent to no transmission of an ACP Packet.
ACP_Type = 0 : Generic Audio
ACP_Type_Dependent fields all Reserved (0).
9.3.4
Application to IEC 60958-Identified Audio
A Source may indicate that the Sink must support the proper output of SCMS bits by setting
ACP_Type = 1 (Type 1 = IEC 60958-identified).
ACP_Type = 1 : IEC 60958-identified
ACP_Type_Dependent fields all Reserved (0).
9.3.5
Application to DVD-Audio
Whenever a Source is transmitting DVD-Audio content for which HDCP is required, an accurate
ACP Packet, with ACP_Type = 2 shall be transmitted at least once per 300msec.
The UPC/EAN and/or ISRC values are recorded on the DVD-Audio disc with DVD audio data.
When the Source transmits UPC/EAN and/or ISRC using ISRC packet, the time lag between the
ISRC packet and the corresponding audio sample packet should be minimized.
ACP_Type = 2 : DVD-Audio
ACP_Type_Dependent Usage:
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Table 9-1 ACP_Type Dependent Fields for DVD-Audio Application
Packet
Byte #
7
6
4
3
2
1
0
DVD-Audio_Type_Dependent_Generation
PB0
PB1
5
Copy_Permission
Copy_Number
Quality
Transaction
PB2
:
:
Reserved (0)
PB27
DVD-Audio_Type_Dependent_Generation
[8 bits] Identifies the generation of the
DVD-Audio-specific ACP_Type_Dependent fields. Shall be set to 1. In the future version
of this specification, currently reserved field(s) may be used to carry additional information.
In such case, the value of this field may be incremented.
Copy_Permission
[2 bits] audio_copy_permission parameter.
Copy_Number
[3 bits] audio_copy_number parameter.
Quality
[2 bits] audio_quality parameter.
Transaction
[1 bit] audio_transaction parameter.
See “DVD Specifications for Read-Only Disc, Part 4: AUDIO SPECIFICATIONS”, Version 1.2,
Table 7.2.3.1.1-2”, and “Supplement to Part 4: AUDIO SPECIFICATIONS Version 1.2 (February
2004)” for descriptions and use of the fields: audio_copy_permission, audio_copy_Number,
audio_quality, and audio_transaction.
Any Source that supports DVD-Audio transmission on HDMI shall have the ability to transmit all
valid channels of any multi-channel content.
9.3.6
Application to Super Audio CD
Whenever a Source is transmitting content originally derived from the HD Layer of a Super Audio
CD, an accurate ACP Packet with ACP_Type = 3 shall be transmitted at least once per 300msec.
See Super Audio CD System Description for “HD Layer Content”.
ACP_Type = 3 : Super Audio CD
ACP_Type_Dependent Usage:
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Table 9-2 ACP_Type Dependent Fields for Super Audio CD Application
Packet
Byte #
7
6
5
4
3
2
1
0
PB0
:
:
CCI_1
PB15
PB16
:
:
Reserved (0)
PB27
CCI_1 [16 bytes] Additional content control information. See Super Audio CD System
Description for details.
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Appendix A
A.1
Version 1.4b
Repeater
Repeater Functions
A Repeater is defined as a device with one or more HDMI inputs, one or more HDMI outputs, and
a retransmission function.
A Repeater has at least one of following functions:
Repeat function:
Single-input, single-output devices. Used primarily for cable extension.
Switch function:
Multiple-input, single-output devices. Used primarily to select among multiple Sources.
Distributor function:
Single-input, multiple-output devices, where only one output is active. Used primarily to select
among multiple displays or Sinks.
Duplicator function:
Single-input, multiple-output devices, where more than one output is active. Used for signal
distribution.
Combinations of the above, for instance, multiple-input, multiple-output devices, incorporating both
input selection and output selection or signal distribution are allowed.
In all cases, each HDMI input shall fulfill all of the requirements of an HDMI Sink when it is
connected with an active sink device, and each HDMI output shall fulfill all of the requirements of
an HDMI Source when it is connected with an active source.
The E-EDID presented by a Repeater should reflect the capabilities of the downstream Sink.
A.2
E-EDID Read Timing (Informative)
In terms of E-EDID handling, Repeaters will typically fall into one of the following categories.
Stored E-EDID type: The Repeater stores an E-EDID data structure that typically consists of
downstream Sink capabilities.
Forwarding type: The Repeater does not store an E-EDID data structure. When an E-EDID
read request comes from a Source, the Repeater forwards the read request to a Sink. The
E-EDID data from the Sink is then forwarded back to the Source.
An HDMI cluster may have several Repeaters between a Source and a Sink. To minimize the
impact to the E-EDID reading time, each Repeater in the chain should minimize the added delay.
For example, the delay added by a Forwarding type Repeater should be no more than 4 msec per
16-byte read.
A stored E-EDID type Repeater should be able to send a 256 byte E-EDID within 150 msec when
a Source issues sixteen 16-byte read requests. This means that a 16-byte read request would be
completed within approximately 10 msec.
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Appendix B
B.1
Version 1.4b
Type B Connector Usage
Exception To Audio Format Support Requirement
Sources are not required to carry audio when all of the following conditions are met:
Source is required by the HDMI Specification or associated agreements to use the Type B
connector, and,
Source has alternate default or user selectable audio outputs, and,
Source can ensure that the appropriate audio stream is being delivered to the alternate audio
outputs.
In order to guarantee rendering of video from Sources that do not fully support HDMI audio, the
following condition shall be met:
Sinks that are capable of supporting an HDMI video format when it is accompanied by audio
shall also support that format when it is not accompanied by audio.
It is strongly recommended that a display device, when receiving an HDMI video signal without
audio, temporarily indicate to the user that there is no audio accompanying the stream.
B.2
HDMI Dual-Link Architecture
HDMI dual-link architecture is compatible with DVI 1.0 dual-link architecture. Refer to section 3.1.5
of the DVI 1.0 specification.
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Appendix C
C.1
Version 1.4b
Compatibility With DVI
Requirement for DVI Compatibility
All HDMI Sources shall be compatible with DVI 1.0 compliant sink devices (i.e. “monitors” or
“displays”) through the use of a passive cable converter. Likewise, all HDMI Sinks shall be
compatible with DVI 1.0 compliant sources (i.e. “systems” or “hosts”) through the use of a similar
cable converter.
When communicating with a DVI device, an HDMI device shall operate according to the DVI 1.0
specification, with the following exception – these devices are not required to comply with DVI 1.0
rules regarding:
Monitor scaling requirements [refer to Section 2.2.8.2 of the DVI specification – superseded by
HDMI specifications]
Physical Interconnect specifications [refer to Chapter 5 of the DVI specification – superseded
by HDMI specifications]
System Low Pixel Format Support Requirements [refer to Section 2.2.4 of the DVI
specification – superseded by HDMI specifications]
Furthermore, for HDMI devices that would not otherwise have a “BIOS” or “operating system”
there are the following additional exceptions:
“BIOS” requirements [refer to Section 2.2.4 of the DVI specification]
“Operating system” requirements [refer to Section 2.2.2 and Section 2.2.9 of the DVI
specification]
“System level event” requirements [refer to Section 2.2.9.1 of the DVI specification]
Power management requirements [refer to Section 2.4 of the DVI specification]
C.2
HDMI Source Requirements
When communicating with a DVI sink device, an HDMI Source shall operate in a mode compatible
with that device. This requires that the Source operate under the following limitations:
Video pixel encoding shall be RGB.
No Video Guard Bands shall be used.
No Data Islands shall be transmitted.
An HDMI Source may transmit Video Data Periods without Guard Bands only when
communicating to a DVI sink device or during the process of determining if the sink device is HDMI
capable.
An HDMI Source, upon power-up, reset or detection of a new sink device, shall assume that the
sink device operates under DVI 1.0 limitations. An HDMI Source shall determine if the sink device
is an HDMI Sink by following the rule(s) described in Section 8.3.5. Upon detection of an HDMI
Sink, the HDMI Source shall follow all of the HDMI Source-related requirements specified in this
document.
All electrical and physical specifications in Section 4 shall be followed by the HDMI Source even
when communicating with a DVI sink device.
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C.3
Version 1.4b
HDMI Sink Requirements
When connected to a DVI source device, an HDMI Sink shall operate as a DVI 1.0 compliant sink
with the exceptions outlined in Section C.1 above.
A DVI source device will always be restricted in the following ways:
Only RGB pixel encoding is used.
There is no Guard Band on the Video Data Period.
There are no Data Islands transmitted.
An HDMI Sink, upon power-up, reset or detection of a new source device, shall assume that the
source device is limited to the above behavior. Upon the detection of an indication that the source
is HDMI-capable, the HDMI Sink shall follow all of the HDMI Sink-related requirements specified in
this document.
All electrical and physical specifications in Section 4 of the HDMI Specification shall be followed by
the HDMI Sink even when communicating with a DVI source device.
C.4
Type A to DVI Adapter Cable [Informative]
Table C-1 Wire Categories
Category
A
B
C
D
N.C.
5V
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TMDS Signal Wire
TMDS Shield
Control
Control Ground
No connect (no wire)
5 Volts Power Wire
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Version 1.4b
Table C-2 Type A-to-DVI-D Cable Wire Assignment [Informative]
Type A
pin
Signal Name
Wire
DVI-D pin
1
TMDS Data2+
A
2
2
TMDS Data2 Shield
B
3
3
TMDS Data2–
A
1
4
TMDS Data1+
A
10
5
TMDS Data1 Shield
B
11
6
TMDS Data1–
A
9
7
TMDS Data0+
A
18
8
TMDS Data0 Shield
B
19
9
TMDS Data0–
A
17
10
TMDS Clock+
A
23
11
TMDS Clock Shield
B
22
12
TMDS Clock–
A
24
15
SCL
C
6
16
DDC Data
C
7
17
DDC/CEC Ground
D
15
18
+5V Power
5V
14
19
Hot Plug Detect
C
16
13
CEC
N.C.
14
Reserved (in cable but N.C. on device)
N.C.
TMDS Data 4-
N.C.
4
TMDS Data 4+
N.C.
5
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TMDS Data 3-
N.C.
12
TMDS Data 3+
N.C.
13
TMDS Data 5-
N.C.
20
TMDS Data 5+
N.C.
21
No Connect
N.C.
8
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C.5
Version 1.4b
Type B to DVI Adapter Cable [Informative]
Table C-3 Type B to DVI-D Cable Wire Assignment [Informative]
Type B pin
Pin Assignment
Wire
DVI-D pin
1
TMDS Data2+
A
2
2
TMDS Data2 Shield
B
3
3
TMDS Data2-
A
1
4
TMDS Data1+
A
10
5
TMDS Data1 Shield
B
11
6
TMDS Data1-
A
9
7
TMDS Data0+
A
18
8
TMDS Data0 Shield
B
19
9
TMDS Data0-
A
17
10
TMDS Clock+
A
23
11
TMDS Clock Shield
B
22
12
TMDS Clock-
A
24
13
TMDS Data5+
A
21
14
TMDS Data5 Shield
B
19
15
TMDS Data5-
A
20
16
TMDS Data4+
A
5
17
TMDS Data4 Shield
B
3
18
TMDS Data4-
A
4
19
TMDS Data3+
A
13
20
TMDS Data3 Shield
B
11
21
TMDS Data3-
A
12
25
SCL
C
6
26
DDC Data
C
7
27
DDC/CEC Ground
D
15
28
+5V Power
5V
14
29
Hot Plug Detect
C
16
22
CEC
N.C.
23
Reserved
N.C.
24
Reserved
N.C.
No Connect
N.C.
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High-Definition Multimedia Interface Specification
Appendix D
D.1
Version 1.4b
Deep Color Additional Detail
State Machines
The following state machine drawings are provided for informative purposes to provide better
understanding of the Deep Color packing sequences. For each mode, the source sequence starts
at phase 0, and then increments through the phases. While DE=1 (pixel data is available), pixel
data fragments mPn are transmitted. While DE=0, blanking fragments mCn are transmitted.
24 bit mode:
DE=0
8P0
AA
DE=1
DE=1
8C0
S
DE=0
30 bit mode:
10P0
AAAA
10C0
S
DE=1
DE=0
10P1
ABBB
DE=1
10C1
T
10P2
BBCC
DE=1
DE=0
10PC2
T
10C2
U
DE=1
DE=0
10P3
CCCD
DE=1
DE=1
DE=0
DE=0
10PC3
U
10C3
V
10PC4
V
10C4
(V)
DE=0
10P4
DDDD
DE=1
DE=1
DE=0
DE=0
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36 bit mode:
12P0
AA
12C0
S
DE=1
12P1
AB
DE=0
12C1
T
DE=0
DE=1
12P2
BB
DE=1
12C2
(T)
DE=0
DE=1
DE=0
48 bit mode:
16P0
AA
16C0
S
16P1
AA
16C1
(S)
DE=0
DE=1
D.2
DE=1
DE=0
Recommended N and Expected CTS Values
The recommended value of N for several standard pixel clock rates at several Deep Color modes
are shown below. It is recommended that Sources with non-coherent clocks use the values listed
for a TMDS clock of “Other”.
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Table D-1 36 bits/pixel: Recommended N and Expected CTS for 32kHz
32 kHz
Pixel Clock (MHz)
N
CTS
25.2 / 1.001
9152
84375
25.2
4096
37800
27
4096
40500
27 1.001
8192
81081
54
4096
81000
54 1.001
4096
81081
11648
316406-316407*
4096
111375
11648
632812-632813*
148.5
4096
222750
Other
4096
Measured
74.25 / 1.001
74.25
148.5 / 1.001
* Note: This value will alternate because of restriction on N.
Table D-2 36 bits/pixel: Recommended N and Expected CTS for 44.1kHz and Multiples
44.1 kHz
Pixel Clock (MHz)
88.2 kHz
176.4 kHz
N
CTS
N
CTS
N
CTS
25.2 / 1.001
7007
46875
14014
46875
28028
46875
25.2
6272
42000
12544
42000
25088
42000
27
6272
45000
12544
45000
25088
45000
27 1.001
6272
45045
12544
45045
25088
45045
54
6272
90000
12544
90000
25088
90000
54 1.001
6272
90090
12544
90090
25088
90090
17836
351562-351
563*
35672
351562-351
563*
71344
351562-351
563*
6272
123750
12544
123750
25088
123750
17836
703125
35672
703125
71344
703125
148.5
6272
247500
12544
247500
25088
247500
Other
6272
measured
12544
measured
25088
measured
74.25 / 1.001
74.25
148.5 / 1.001
* Note: This value will alternate because of restriction on N.
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Version 1.4b
Table D-3 36 bits/pixel: Recommended N and Expected CTS for 48kHz and Multiples
48 kHz
Pixel Clock (MHz)
96 kHz
192 kHz
N
CTS
N
CTS
N
CTS
25.2 / 1.001
9152
56250
18304
56250
36608
56250
25.2
6144
37800
12288
37800
24576
37800
27
6144
40500
12288
40500
24576
40500
27 1.001
8192
54054
16384
54054
32768
54054
54
6144
81000
12288
81000
24576
81000
54 1.001
6144
81081
12288
81081
24576
81081
11648
210937-210
938*
23296
210937-210
938*
46592
210937-210
938*
6144
111375
12288
111375
24576
111375
11648
421875
23296
421875
46592
421875
148.5
6144
222750
12288
222750
24576
222750
Other
6144
measured
12288
measured
24576
measured
74.25 / 1.001
74.25
148.5 / 1.001
* Note: This value will alternate because of restriction on N.
Table D-4 48 bits/pixel: Recommended N and Expected CTS for 32kHz
32 kHz
Pixel Clock (MHz)
N
CTS
25.2 / 1.001
4576
56250
25.2
4096
50400
27
4096
54000
27 1.001
4096
54054
54
4096
108000
54 1.001
4096
108108
11648
421875
4096
148500
11648
843750
148.5
4096
297000
Other
4096
Measured
74.25 / 1.001
74.25
148.5 / 1.001
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Table D-5 48 bits/pixel: Recommended N and Expected CTS for 44.1kHz and Multiples
44.1 kHz
Pixel Clock (MHz)
88.2 kHz
176.4 kHz
N
CTS
N
CTS
N
CTS
25.2 / 1.001
7007
62500
14014
62500
28028
62500
25.2
6272
56000
12544
56000
25088
56000
27
6272
60000
12544
60000
25088
60000
27 1.001
6272
60060
12544
60060
25088
60060
54
6272
120000
12544
120000
25088
120000
54 1.001
6272
120120
12544
120120
25088
120120
17836
468750
35672
468750
71344
468750
74.25
6272
165000
12544
165000
25088
165000
148.5 / 1.001
8918
468750
17836
468750
35672
468750
148.5
6272
330000
12544
330000
25088
330000
Other
6272
measured
12544
measured
25088
measured
74.25 / 1.001
Table D-6 48 bits/pixel: Recommended N and Expected CTS for 48kHz and Multiples
48 kHz
Pixel Clock (MHz)
96 kHz
192 kHz
N
CTS
N
CTS
N
CTS
25.2 / 1.001
6864
56250
13728
56250
27456
56250
25.2
6144
50400
12288
50400
24576
50400
27
6144
54000
12288
54000
24576
54000
27 1.001
6144
54054
12288
54054
24576
54054
54
6144
108000
12288
108000
24576
108000
54 1.001
6144
108108
12288
108108
24576
108108
11648
281250
23296
281250
46592
281250
74.25
6144
148500
12288
148500
24576
148500
148.5 / 1.001
5824
281250
11648
281250
23296
281250
148.5
6144
297000
12288
297000
24576
297000
Other
6144
measured
12288
measured
24576
measured
74.25 / 1.001
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High-Definition Multimedia Interface Specification
Appendix E
E.1
Version 1.4b
Gamut-Related Metadata
Overview
Unlike the classic colorimetry standards used for standard definition and high definition video, the
enhanced colorimetry of xvYCC has a virtually unconstrained gamut, which does not easily map to
the real-world gamut of existing or near-future display technologies. When transmitting such an
enhanced colorimetry, it is necessary for the video source to also indicate the color gamut of the
transmitted video. This metadata allows the display to map the gamut of the video stream more
accurately and more predictably onto the gamut of the display.
The gamut describes all colors that are reproducible by a particular reference display or that are
present in a given content. The color gamut can be described by a Gamut Boundary Description
(GBD). When a given image content has a gamut larger or different from the gamut of the HDMI
sink, the colors lying outside the aimed gamut need to be clipped or moved accordingly. This
procedure is called gamut mapping. The gamut of the content is circumscribed by the gamut of the
HDMI source color space. The display can then use the content’s Gamut Boundary Description to
perform accurate and predictable mapping onto its own gamut.
E.2
Transmission Profiles
There are several transmission profiles (P0, P1, etc.) for gamut related metadata. The difference
between the transmission profiles is primarily the transmission rate, specifically, the number of
packets that may be sent per video field. Because of the need to transmit the entire metadata
within a short period of time, this transmission rate limits the maximum size of the profile as well.
The maximum size of the metadata then also corresponds to the accuracy of the gamut boundary
description.
The lowest speed transmission profile is P0, transmitting at a rate of one Gamut Metadata Packet
per video field. P0 metadata fits completely within that one packet.
When transmitting GBD data, the Source shall send the GBD for an upcoming gamut change
using P0 transmission profile if that GBD is available prior to transmission of the content. This P0
transmission should occur at least one full video field prior to the start of the new gamut video.
E.3
Gamut Boundary Description
The HDMI source gamut is described either by a set of R/G/B range limits or by a set of vertices
with or without indexed facets. The Format_Flag field indicates which format is supplied:
Format_Flag
[1 bit] Identifies whether subsequent data describes gamut range
boundary or gamut vertices boundary. A value of 0 indicates vertices/facets description. 1
indicates range description.
Two simple GBD data structures: one based on four vertices and the other based on R/G/B
min/max range limits, are fully defined here and may be supported using the P0 transmission
profile. Larger data structures carrying many more vertices as well as facets, will be defined in a
future international specification, not necessarily the HDMI Specification. These data structures
will require higher transmission speeds and sizes and therefore will require higher transmission
profiles (P1...).
After those data structures are defined, a subsequent version of the HDMI Specification will permit
HDMI devices to support them. Until that time, no HDMI Source may transmit a GBD with more
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than four vertices or containing facet data, nor may any Sink indicate support for transmission
profiles other than P0 in the Colorimetry Data Block in the EDID.
Facet data descriptions below are informative only. The facet data structures and relationship
between facets and vertices will be described in a future specification.
The size of each component of each vertex or range entry is indicated in the field
GBD_Color_Precision:
GBD_Color_Precision
0b00
8 bit
0b01
10 bit
0b10
12 bit
[2 bits] Color precision of GBD vertex and range data:
The definition of vertex data depends on the GBD_Color_Space field (see below) and is as
follows:
RGB: Unsigned integer. According to ITU-R 709-5 item 6.10 (8 bit), summarized in Section 6.6
(for 8...16 bit).
xvYCC: Unsigned integer. According to IEC 61966-2-4 item 4.4, summarized in Section 6.6
XYZ: Not valid. Future versions of this specification will further define XYZ tristimulus. Until
that point, XYZ shall not be used for GBD data.
The precision of the facet data (Packed_GBD_Facets_Data in Table E-1 ) depends on the number
of vertices (Number_Vertices) according to the following equation:
Precision [number of bits] of color facet data = ld(Number_Vertices)
Where ld() is the logarithm to the base of two. The format of color facet data is positive integer,
each color facet data indicating the index of a vertex in the Packed_GBD_Vertices_data field. For
example, the integer 0 indicates the first vertex in Packed_GBD_Vertices_data and the integer 1
indicates the second vertex in Packed_GBD_Vertices_data. Three consecutive facets data define
one triangle with surface normal pointing outside the gamut.
The definition of 8/10/12-bit range data is as follows:
8-bit: signed fixed-point – 1 sign bit, 2 bits integer, 5 bits fraction
10-bit: signed fixed-point – 1 sign bit, 2 bits integer, 7 bits fraction
12-bit: signed fixed-point – 1 sign bit, 2 bits integer, 9 bits fraction
These values are not two’s complement but instead, the integer and fraction are both absolute
values. For instance, -0.853 (12-bit) is represented as 0x9B5 (sign=1, 0.853x512=437=0x1B5).
Likewise, 0 = -0.0 or +0.0 = 0x000 or 0x800.
The value of a particular N-bit binary number of the range data representation is given by the
following expression.
N Color Precision ( 8, 10 or 12)
bi bit value ( MSB is bN 1 , LSB is b0 )
sign bit : bN 1 | integer : bN 2 , bN 3 | fraction : bN 4 , , b0
1b
N 2
N 1
2 N 3 2 n bn range _ data
n 0
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The data structures for these two different formats are shown in Table E-1 and Table E-2 .
Table E-1 Vertices/Facets GBD Data Structure
Byte #
7
6
5
4
0
Format_
Flag = 0
Facet_
Mode
Rsvd(0)
3
2
GBD_Color_Precision
1
Number_Vertices_H
2
Number_Vertices_L
3...VSIZ
E+2
Packed_GBD_Vertices_Data[0... VSIZE-1]
VSIZE+
3
Number_Facets_H
VSIZE+
4
Number_Facets_L
VSIZE+
5...
Packed_GBD_Facets_Data[0...FSIZE-2]
VSIZE+
FSIZE+
4
Packed_GBD_Facets_Data[FSIZE-1]
1
0
GBD_Color_Space
Facet_Mode
[1 bit] Indicates if Facets are also included in the GBD. Field is valid
only when Format_Flag = 0. Reserved (0) when Format_Flag = 1.
GBD_Color_Precision
GBD_Color_Space
[3 bits] Color space of GBD data:
0b000 ITU-R BT.709 (using RGB)
0b001 xvYCC601 (IEC 61966-2-4 – SD) (using YCBCR)
0b010 xvYCC709 (IEC 61966-2-4 – HD) (using YCBCR)
0b011 XYZ (see above)
Number_Vertices(_H, _L)
structure.
[2 bytes] Number of vertices described by following
Number_Facets(_H, _L)
[2 bytes] Number of facets described by following structure.
[2 bits] see above
VSIZE is the number of bytes in the Packed_GBD_Vertices_Data according to:
VSIZE INT 3 Number _ Vertices GBD _ Color _ Pr ecision / 8 0.99999
Where, INT() is a function returning the integer part of the number (e.g. INT(3.99999...) = 3).
FSIZE is the number of bytes of Packed_GBD_Facets_Data and will be defined in a future
specification.
The minimal number of vertices is 4. In this case, and only this case, the vertices have the
following meaning, in this order: black point, red primary, green primary and blue primary. This
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convention allows constructing the white point and the secondary colors (magenta, cyan and
yellow) without transmission.
Table E-2 Range GBD Data Structure
Byte #
7
6
5
0
Format_
Flag = 1
Rsvd(0)
Rsvd(0)
1...N
4
3
2
GBD_Color_Precision
1
0
GBD_Color_Space
Packed_Range_Data
Packed_Range_Data
sequence:
Min_Red_Data
Max_Red_Data
Min_Green_Data
Max_Green_Data
Min_Blue_Data
Max_Blue_Data
[N bytes] Packed range data according to following
GBD_Color_Precision
[2 bits] see above
GBD_Color_Space
[3 bits] Color space of GBD data:
0b000 Reserved
0b001 RGB expression of xvYCC601 coordinates
0b010 RGB expression of xvYCC709 coordinates
0b011 Reserved
:
:
0b111 Reserved
Note: RGB expression of xvYCC601 coordinates should be processed as
same as RGB expression of xvYCC709 coordinates. RGB expression of
xvYCC601 coordinates in GBD_Color_Space is not defined in IEC 61966-2-4.
E.4
Data Packing
GBD data is efficiently packed with each 8-, 10- and 12-bit value taking exactly 8-, 10- or 12-bits in
the packet. The GBD_Color_Precision field specifies the packing and precision of the GBD data.
Table E-3 and Table E-4 define the packing for 10- and 12-bit values using a representative
sequence of values, A, B, C..., with A_low representing the low-order bits and A_high, the
high-order bits of value A.
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Table E-3 10-bit Packing
7
6
5
0
1
4
3
1
0
A_high
A_low
2
B_high
B_low
3
C_high
C_low
D_high
4
D_low
5
E_high
6
2
E_low
7
F_high
F_low
G_high...
Table E-4 12-bit Packing
7
6
5
0
1
4
3
A_low
3
C_high
E.5
0
B_high
B_low
5
1
A_high
2
4
2
C_low
D_high
D_low
Example P0 Data Structures
A simple but useful vertex GBD data structure is defined in Table E-5 and can be transmitted using
a single Gamut Metadata Packet, fitting within the P0 transmission profile.
The gamut is described in xvYCC709 space at 8-bit. The GBD consists of black point as well as red,
green and blue primaries.
This data structure has the minimum number of vertices. Following the specification, the
correspondence of transmitted vertices and primaries and black point is given. To reconstruct the
full gamut boundary description, the white point vertex VWHITE and the secondary colors
( VMAGENTA , VCYAN , VYELLOW for magenta, cyan and yellow, respectively) are generated from the
first primaries as follows:
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VWHITE V RED VGREEN VBLUE 2VBLACK
VMAGENTA V RED VBLUE VBLACK
VCYAN VGREEN VBLUE VBLACK
VYELLOW VRED VGREEN VBLACK
Table E-5 P0 Vertices-Only Data – 8-bit Precision Example
Byte #
7
6
5
4
0
Format_
Flag = 0
Facet_
Mode = 0
Rsvd = 0
3
GBD_Color_Precision
= 00
1
Number_Vertices_H = 0
2
Number_Vertices_L = 4
3
Black(Y)
4
Black(CB)
5
Black(CR)
6
Red(Y)
7
Red(CB)
8
Red(CR)
9
Green(Y)
10
Green(CB)
11
Green(CR)
12
Blue(Y)
13
Blue(CB)
14
Blue(CR)
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2
1
0
GBD_Color_Space
= 010
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A typical range GBD data structure is shown in Table E-6 . This can be transmitted using a single
Gamut Metadata Packet, fitting within the P0 transmission profile. The gamut is described in
xvYCC709 space at 12-bit. The GBD consists of min_red_data, max_red_data, min_green_data,
max_green_data, min_blue_data, and max_blue_data
Table E-6 P0 Range Data – 12-bit Precision Example
Byte #
7
6
5
0
Format_
Flag = 1
Rsvd = 0
Rsvd = 0
1
2
4
3
GBD_Color_Precision
= 10
Min_Red_Data_L
4
Min_Green_Data_H
Min_Green_Data_L
Max_Green_Data_L
7
Min_Blue_Data_H
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= 010
Max_Green_Data_H
6
9
0
Max_Red_Data_H
Max_Red_Data_L
8
1
Min_Red_Data_H
3
5
2
Min_Blue_Data_L
Max_Blue_Data_H
Max_Blue_Data_L
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Appendix F
Version 1.4b
Video Scaling Auto-Configuration
Informative Appendix
In addition to any other mode that a source provides, it is highly recommended that it also provide
a pass-through mode of operation. In the pass-through mode the source will pass video
unprocessed to its output, if the format is supported by the display, without scaling or
de-interlacing (except for performing any necessary field repeats, for instance to show 720p24Hz
content on a display with only a 720p60Hz input capability).
In the case that the source cannot send the video in pass-through mode (because the format is not
supported by the display), it should convert to the highest priority format as indicated by the DTDs
and SVDs, with the first DTD (“Preferred”) being the highest priority.
In the case that the source cannot send the video in pass-through mode (format not supported by
the display), and it can also not convert to the preferred video format, the source should select the
highest resolution progressive video format supported by the display.
Note: in order to allow displays to indicate a wide range of supported video formats, the source
must be able to read EDID information from all defined blocks and must read and understand
DTDs and SVDs as defined in CEA-861-D.
The source may also provide a “film-mode” de-interlacer to convert interlaced format video to its
original progressive format. It should then consider such converted video as progressive, for
instance 480i 60Hz video should be considered as 480p 24Hz video after successful film mode
conversion.
It is strongly recommended that displays that cannot perform film-mode de-interlacing on an
interlaced video format do not list such an interlaced format as the preferred format but list such a
format with a priority (in the list of DTDs and SVDs) that corresponds to the effective resolution.
For instance, a display that cannot do film-mode de-interlacing on 1080i may list this format with a
priority roughly equivalent to 540 progressive lines.
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Appendix G
Version 1.4b
Reserved
(This page is intended to be blank.)
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High-Definition Multimedia Interface Specification
Appendix H
Version 1.4b
3D video formats extensions
Note: The following is a preliminary draft subject to change without notice. Adopter may use this in
its own discretion.
H. 1
HDMI Vendor Specific InfoFrame extension
In some cases, the HDMI Vendor Specific InfoFrame packet described in section 8.2.3 is extended
as follows. When HDMI_Video_Format is set to 010, the 3D_Meta_present bit may be set (=1). If
the 3D_Meta_present bit is set (=1), it indicates the presence of detailed information as defined in
subsection "3D_Meta fields" below.
Table H-1 HDMI Vendor Specific InfoFrame Packet Contents
Packet Byte #
7
6
5
PB0
4
3
2
1
0
Rsvd
(0)
Rsvd
(0)
Rsvd
(0)
Rsvd
(0)
Rsvd
(0)
Rsvd
(0)
Checksum
PB1
PB2
24bit IEEE Registration Identifier (0x000C03)
( least significant byte first )
PB3
PB4
HDMI_Video_Format
Rsvd
(0)
Rsvd
(0)
HDMI_VIC
(PB5)
3D_Met
a_prese
nt
3D_Structure
(PB6)
(PB7)
3D_Ext_Data
Reserved(0)
3D_Metadata_type
3D_Metadata_Length (= N)
(PB8)
3D_Metadata_1
…
…
(PB [7+N])
3D_Metadata_N
PB[8+N] ~ [Nv]
Reserved (0)
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3D_Structure field
In addition to the Frame packing value “0000”, Side-by-Side (Half) value “1000” and
Top-and-Bottom value “0110” specified in Section 8.2.3, additional values for 3D_Structure are
defined below in Table H-2.
3D_Structure
data.
[4bits] This 4 bit field defines the transmission format of 3D video
Table H-2 3D_Structure
Value
Meaning
0000
Frame packing
0001
Field alternative
0010
Line alternative
0011
Side-by-Side (Full)
0100
L + depth
0101
L + depth + graphics + graphics-depth
0110
Top-and-Bottom
0111
Reserved for future use.
1000
Side-by-Side (Half)
(See Table H-3)
1001 ~ 1110
Reserved for future use.
1111
Not in use
3D_Ext_Data field
In addition to the value "00XX" (horizontal subsamling) specified in Section 8.2.3, additional values
for 3D_Ext_Data are defined below in Table H-3.
3D_Ext_Data
[4bits] The meaning of this field depends on the 3D_Structure value.
If 3D_Structure is 1000 (Side-by-Side (Half)), the 3D_Ext_Data field and also the 4-bit
reserved field in the same byte is added in the HDMI Vendor Specific InfoFrame and
indicates additional information about the 3D format.
Table H-3 3D_Ext_Data –- Additional video format information for 3D_Structure = 1000
3D_Ext_Data
Meaning
00XX
(0000, 0001, 0010, 0011)
Horizontal sub-sampling
0100
Quincunx
matrix
0101
Odd/Left picture, Odd/Right picture
Odd/Left picture, Eveen/Right picture
0110
Even/Left picture, Odd/Right picture
0111
Even/Left picture, Even/Right picture
1000 ~ 1111
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With respect to the quincunx matrix case, the sub-sampling position interchanges on every line of
the original full left and right pictures as shown in Figure H-1.
Odd position
Even position
Figure H-1 Quincunx sub-sampling method and its position on the original full picture
3D_Meta field
3D_Meta_present
[1bit] if set (=1) then a few additional bytes of 3D metadata (i.e.
3D_Metadata_type, 3D_Metadata_Length and 3D_Metadata_1…N)
follow in the HDMI Vendor Specific InfoFrame.
3D_Metadata_type
[3bits] These 3 bits define an optional metadata type that
accompanies the stereoscopic video for correct rendering in the display. The semantics of
the bytes 3D_Metadata1…N depend on the type of data as indicated in Table H-4.
Table H-4 3D_Metadata_type
Value
000
001 ~ 111
Meaning
The following 3D_Metadata_1…N contains the parallax
information as defined in ISO23002-3 sections 6.1.2.2 and
6.2.2.2
Reserved for future use
3D_Metadata_Length
[5bits] These 5 bits show the length of following 3D_Metadata_1…N
byte. In case of 3D_Metadata_type = 000, then 3D_Metadata_Length = 8 according to
ISO23002-3 section 6.1.2.2.
3D_Metadata_1…N
[N bytes] These bytes depend on 3D_Metadata_type value.
In case of 3D_Metadata_type = 000, 3D_Metadata_1…8 is filled with following values:
3D_Metadata_1 = parallax_zero[15…8]
3D_Metadata_2 = parallax_zero[7…0]
3D_Metadata_3 = parallax_scale [15…8]
3D_Metadata_4 = parallax_scale [7…0]
3D_Metadata_5 = dref [15…8]
3D_Metadata_6 = dref [7…0]
3D_Metadata_7 = wref[15…8]
3D_Metadata_8 = wref[7…0]
Regarding the parallax parameter, refer to ISO23002-3 section 6.2.2.2.
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H. 2
Version 1.4b
3D video formats structure extension
Various 3D video formats may optionally be transmitted. The 3D video format is indicated by using
the VIC field in the AVI InfoFrame in conjunction with any of the extended 3D_Structure values
defined in Table H-2 in the HDMI Vendor Specific InfoFrame.
Field alternative, indicated by the 3D_Structure field =0001, is defined as shown in Figure H-2.
Line alternative, indicated by the 3D_Structure field =0010, is defined as shown in Figure H-3.
Side-by-Side (Full), indicated by the 3D_Structure field =0011, is defined as shown in Figure H-4.
L+Depth, indicated by the 3D_Structure field =0100, is defined as shown in Figure H-5.
L+Depth+Gfx+Gfx-depth, indicated by the 3D_Structure field =0100, is defined as shown in Figure
H-6.
Vertical blanking signal
2D_V detail
3D_V1 detail
Hactive(pixel)
Vblank – 0.5(line)
Hblank(pixel)
Hactive(pixel)
Vblank – 0.5 (line)
odd
Vactive(line)
Vblank + 0.5 (line)
Vactive(line)
2D vertical
total line
even
Vactive(line)
2 / Vfreq (sec)
1/ Vfreq(sec)
Hblank(pixel)
L odd
Vblank + 0.5 (line)
Vactive(line)
R odd
3D
vertical
total line
Vblank – 0.5 (line)
2D horizontal total pixel
3D_V3 detail
2D video
-
3D_V2 detail
3D horizontal total pixel is equal to 2D horizontal total pixel.
3D vertical total line is x2 of 2D vertical total line.
3D pixel clock frequency is x2 of 2D pixel clock frequency.
Vactive is number of active lines per field
This structure can be applied only for interlaced video format.
3D_V1_detail
2D_V detail
Vertical blanking signal
Vactive(line)
Vblank – 0.5
Vback
Vblank – 0.5 Vback2
Vsync2 = Vsync – 0.5
Vback2 = Vback + 0.5
R even
3D horizontal total pixel
3D_V3_detail
Vfront
Vsync2
Vfront
Vsync
L even
Vblank + 0.5 (line)
V sync signal
Vfront
Vsync
Vblank – 0.5
Vback
3D_V2_detail
Vactive(line)
Vblank + 0.5
(no Vsync pulse in
this period)
3D video
(note) This structure is applied only for
interlaced formats, so the value of
Vblank has a fraction of 0.5 line to
indicate that the blanking period of 1st
field and 2nd field is different.
However, in the case of VIC=39, the
blanking period of both fields has the
same value so that the items shown
as “(Vblank – 0.5)“ and "(Vblank +
0.5)" in this figure all have the same
integer value 85.
Figure H-2 3D structure (Field alternative)
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Hblank(pixel)
Hactive(pixel)
Vblank(line)
2 x Vblank(line)
Hactive(pixel)
2D vertical
total line
Vactive(line)
1 st active video of L
1 st active video of R
2 nd active video of L
2 x Vactive(line)
2 nd active video of R
1/ Vfreq(sec)
1/ Vfreq(sec)
Hblank(pixel)
Version 1.4b
2D horizontal total pixel
2D video
3D vertical
total line
3D horizontal total pixel
-
3D horizontal total pixel is equal to 2D horizontal total pixel.
3D vertical total line is x2 of 2D vertical total line.
3D pixel clock frequency is x2 of 2D pixel clock frequency.
This structure can be applied only for progressive video format
3D video
(note)
Vfront, Vback and Vsync of 3D video timing are x2 of the
original video timing which is defined by each VIC.
Figure H-3 3D structure (Line alternative)
Hactive(pixel)
Vblank(line)
-
3D horizontal total pixel is x2 of 2D horizontal total pixel.
3D vertical total line is equal to 2D vertical total line.
3D pixel clock frequency is x2 of 2D pixel clock frequency.
For interlaced formats, Vactive is number of active lines per field.
(note)
Hfront, Hback and Hsync of 3D video timing are x2 of the
original 2D video timing which is defined by each VIC.
2D vertical
total line
Vactive(line)
1/ Vfreq(sec)
Hblank(pixel)
2D horizontal total pixel
2D video
2 x Hactive(pixel)
Vblank(line)
Vactive(line)
1/ Vfreq(sec)
2 x Hblank(pixel)
L
3D video
R
3D vertical
total line
3D horizontal total pixel
Figure H-4 3D structure (Side-by-Side (Full))
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Hblank(pixel)
2D video
Active video
Vact_space(line)
Vactive(line)
Vactive(line)
1/ Vfreq(sec)
2D vertical
total line
2D horizontal total pixel
-
Hactive(pixel)
Vblank(line)
Vblank(line)
Hactive(pixel)
Vactive(line)
1/ Vfreq(sec)
Hblank(pixel)
Version 1.4b
L
3D vertical
total line
Active space
Active video
depth
3D horizontal total pixel is equal to 2D horizontal total pixel.
3D vertical total line is x2 of 2D vertical total line.
3D pixel clock frequency is x2 of 2D pixel clock frequency.
This structure can be applied only for progressive video format
3D horizontal total pixel
3D video
Vact_space = Vblank
Figure H-5 3D structure (L + depth)
Vblank(line)
2D horizontal total pixel
1/ Vfreq(sec)
2D vertical
total line
2D video
-
3D horizontal total pixel is equal to 2D horizontal total pixel.
3D vertical total line is x4 of 2D vertical total line.
3D pixel clock frequency is x4 of 2D pixel clock frequency.
This structure can be applied only for progressive video format
Vactive(line)
Vactive(line)
Vactive(line)
Vactive(line)
Vact_space(line)
Vact_space(line)
Vact_space(line)
Vblank(line)
Hblank(pixel)
Hactive(pixel)
Vactive(line)
1/ Vfreq(sec)
Hblank(pixel)
Hactive(pixel)
Active video
L
3D vertical
total line
Active video
depth
Active video
GFX
Active video
GFX-depth
3D horizontal total pixel
3D video
Vact_space = Vblank
Figure H-6 3D structure (L + depth + Graphics + Graphics-depth )
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The following table shows examples of 3D video formats. Other VICs can be used for 3D video
formats.
Table H-5 3D transmission video size (example)
3D_structure
Correspond
ing figure
VIC
description
Hactive
0001
(Field alternative)
0010
(Line alternative)
0011
(Side-by-Side(Full))
0100
(L+depth)
0101 (L+depth
+Gfx + Gfx-depth)
Figure H-2
Figure H-5
5
20
16
31
16
31
19
1080i, 60Hz
1080i, 50Hz
1080p, 60Hz
1080p, 50Hz
1080p, 60Hz
1080p, 50Hz
720p, 50Hz
1920
1920
1920
1920
1920
1920
1280
Figure H-6
19
720p, 50Hz
1280
Figure H-3
Figure H-4
Hblank
Hfront
Hsync
Hback
280
720
280
720
280
720
700
88
528
88
528
88
528
440
44
44
44
44
44
44
40
148
148
148
148
148
148
220
700
440
40
220
(Continued)
3D
_Structure.
0001
0010
0011
0100
0101
Vactive
540
540
1080
1080
1080
1080
720
720
Vact_space
n.a
n.a.
n.a.
n.a.
n.a.
n.a.
30
30
Vblank
22.5
22.5
45
45
45
45
30
30
Vfront
2
2
4
4
4
4
5
5
Vsync
5
5
5
5
5
5
5
5
Vback
15
15
36
36
36
36
20
20
Pixel freq [MHz]
(note 1)
148.50
148.50
297.00
297.00
297.00
297.00
148.50
297.00
V freq (Hz)
(note 1)
60
50
60
50
60
50
50
50
1. V freq=60Hz and the corresponding Pixel freq include the variation of 1000/1001. The video timing
for pixel and line is the same as 60Hz.
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High-Definition Multimedia Interface Specification
H. 3
Version 1.4b
HDMI Vendor-Specific Data Block (HDMI VSDB) extension
For some formats, additional codings are defined for certain fields in the HDMI Vendor Specific
Data Block.
Table H-6 HDMI-LLC Vendor-Specific Data Block (HDMI VSDB)
Byte #
0
7
6
5
4
3
2
Vendor-specific tag code (=3)
1
1
0
Rsvd
(0)
Rsvd
(0)
DVI_
Dual
CNC2
CNC1
CNC0
Rsvd
(0)
Rsvd
(0)
Rsvd
(0)
Length (=N)
24-bit IEEE Registration Identifier (0x000C03)
(least significant byte first)
2
3
4
A
B
5
C
D
6
Supports
_AI
DC_
48bit
DC_
36bit
DC_
Y444
Latency_
Fields_
Present
I_Latency
_Fields_
Present
HDMI_V
ideo_pr
esent
Rsvd
(0)
CNC3
(9)
Video_Latency
(10)
Audio_Latency
(11)
Interlaced_Video_Latency
(12)
Interlaced_Audio_Latency
(13)
(14)
(15)
extension
fields
Max_TMDS_Clock
7
8
DC_
30bit
3D_prese
nt
3D_Multi_present
Image_Size
HDMI_VIC_LEN
HDMI_3D_LEN
(if HDMI_VIC_LEN > 0)
HDMI_VIC_1
…
HDMI_VIC_M
(if 3D_Multi_present = 01 or 10)
3D_Structure_ALL_15…8
3D_Structure_ALL_7…0
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(if 3D_Multi_present = 10)
3D_MASK_15…8
3D_MASK_7…0
2D_VIC_order_1
3D_Structure_1
3D_Detail_1 ***
Reserved(0) ***
…
2D_VIC_order_L
( )*…N
3D_Structure_L
Reserved (0)**
* The position of these bytes will depend upon the values of Latency_Fields_Present,
I_Latency_Fields_Present and HDMI_Video_present.
** No additional bytes are necessary but if present, they shall be zero.
*** The bytes with 3D_Detail_X and Reserved(0) are present only for some values of 3D_Structure_X. See
below for details.
3D_Structure_ALL_15…0
[2 bytes] For each bit in this field which is set (=1), an HDMI
Sink supports the corresponding 3D_Structure according to Table H-7 for all of the VICs
listed in the first 16 entries in the EDID.
By using this field, the 3D capabilities of an HDMI Sink can be concisely described.
Table H-7 3D_Structure_ALL
Bit
Meaning
3D_Structure_ALL_0
Sink supports “Frame packing” 3D formats.
3D_Structure_ALL_1
Sink supports “Field alternative” 3D formats (for interlaced video timing).
3D_Structure_ALL_2
Sink supports “Line alternative” 3D formats (for progressive video timing)
3D_Structure_ALL_3
Sink supports “Side-by-Side(Full)” 3D formats
3D_Structure_ALL_4
Sink supports “L + depth” 3D formats (for progressive video timing)
3D_Structure_ALL_5
Sink supports “L + depth + graphics + graphics-depth” 3D formats (for
progressive video timing)
3D_Structure_ALL_6
Sink supports “Top-and-Bottom” 3D formats
3D_Structure_ALL_7
Reserved (0)
3D_Structure_ALL_8
Sink supports “Side-by-Side(Half) with horizontal sub-sampling” 3D formats
3D_Structure_ALL_9…14
3D_Structure_ALL_15
Reserved (0)
Sink supports “Side-by-Side(Half) with all quincunx sub-sampling” 3D formats
3D_Structure_X
[4bits] X means the index value from 1 to L. This field indicates the 3D
capability for the corresponding VIC code indicated by 2D_VIC_order_X. The value is
defined in Table H-2.
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3D_Detail_X
[4bits] X means the index value from 1 to L. This field indicates
additional detailed information for the related 3D_Structure_X field.
The values for 3D_Detail_X when 3D_Structure_X = 1000 are defined in Table H-8. In this
case, 3D_Detail_X indicates the supported sub-sampling position(s). 3D_Detail_X = 0001
means that the Sink can handle Horizontal sub-sampling and 0110 means that the Sink
can handle all four sub-sampling positions for Quincunx matrix.
Table H-8 3D_Detail_X for Side-by-Side (Half)
3D_Detail_X
Meaning of supported sub-sampling position.
0000
Support all of the horizontal sub-sampling and four quincunx matrix
0001
Horizontal sub-sampling
0010 ~ 0101
Not in use 1
0110
Support all four combination of sub sampling position
Quincunx
matrix
0111
1000
Odd/Left picture, Odd/Right picture
Odd/Left picture, Even/Right picture
1001
Even/Left picture, Odd/Right picture
1010
Even/Left picture, Even/Right picture
1011 ~ 1111
Reserved
1
The former 1.4 Specification used these values for indicating support for Horizontal
sub-sampling.
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Version 1.4b
Supplement 1
Consumer Electronics Control (CEC)
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CEC Table of Contents
Version 1.4b
CEC Page
CEC 1
INTRODUCTION ............................................................................................................1
CEC 1.1
Normative references.................................................................................................. 1
CEC 1.2
Informative References............................................................................................... 1
CEC 1.3
Document Revision History........................................................................................ 1
CEC 2
DEFINITIONS .................................................................................................................4
CEC 2.1
Conformance Levels ................................................................................................... 4
CEC 2.2
Glossary of Terms ....................................................................................................... 4
CEC 2.3 Usages and Conventions............................................................................................ 4
CEC 2.3.1 State Diagrams........................................................................................................4
CEC 2.3.2 Message Flow Diagrams.........................................................................................5
CEC 2.3.3 Notation ...................................................................................................................5
CEC 3
FEATURE OVERVIEW ..................................................................................................6
CEC 3.1
End-User Features....................................................................................................... 6
CEC 3.2
Supporting Features ................................................................................................... 6
CEC 4
ELECTRICAL SPECIFICATION ....................................................................................7
CEC 5
SIGNALING AND BIT TIMINGS ....................................................................................9
CEC 5.1
CEC Line Usage........................................................................................................... 9
CEC 5.2 Bit Timing ..................................................................................................................... 9
CEC 5.2.1 Start Bit Timing........................................................................................................9
CEC 5.2.2 Data Bit Timing........................................................................................................9
CEC 6
FRAME DESCRIPTION ...............................................................................................12
CEC 6.1 Header/Data Block description ................................................................................ 12
CEC 6.1.1 EOM (End of Message).........................................................................................12
CEC 6.1.2 ACK (Acknowledge) ..............................................................................................13
CEC 6.1.3 Header Block Details.............................................................................................13
CEC 7
RELIABLE COMMUNICATION MECHANISMS .........................................................14
CEC 7.1
Frame Re-transmissions........................................................................................... 14
CEC 7.2
Flow Control............................................................................................................... 14
CEC 7.3
Frame Validation........................................................................................................ 14
CEC 7.4
CEC Line Error Handling .......................................................................................... 14
CEC 8
PROTOCOL EXTENSIONS .........................................................................................16
CEC 9
CEC ARBITRATION ....................................................................................................17
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CEC 9.1
Signal Free Time........................................................................................................ 17
CEC 9.2
Message Time Constraints ....................................................................................... 17
CEC 10
DEVICE CONNECTIVITY AND ADDRESSING ..........................................................18
CEC 10.1 Physical Address Discovery .................................................................................... 18
CEC 10.2 Logical Addressing ................................................................................................... 18
CEC 10.2.1 Logical Address Allocation ...................................................................................20
CEC 10.2.2 Special Devices....................................................................................................21
CEC 10.2.3 Behavior with Earlier Versions .............................................................................23
CEC 11
SWITCH REQUIREMENTS .........................................................................................24
CEC 11.1 CEC Switch................................................................................................................. 24
CEC 12
HIGH LEVEL PROTOCOL...........................................................................................26
CEC 12.1 Source Declaration.................................................................................................... 26
CEC 12.2 Protocol General Rules............................................................................................. 26
CEC 12.3 Feature Abort ............................................................................................................. 27
CEC 12.4 Abort ........................................................................................................................... 28
CEC 13
CEC FEATURES DESCRIPTION................................................................................29
CEC 13.1 One Touch Play ......................................................................................................... 29
CEC 13.1.1 Messages .............................................................................................................29
CEC 13.1.2 Feature Description ..............................................................................................29
CEC 13.1.3 Behavior with Earlier Versions .............................................................................30
CEC 13.2 Routing Control ......................................................................................................... 30
CEC 13.2.1 Messages .............................................................................................................30
CEC 13.2.2 Feature Description ..............................................................................................31
CEC 13.2.3 Behavior with Earlier Versions .............................................................................33
CEC 13.3 System Standby......................................................................................................... 33
CEC 13.3.1 Messages .............................................................................................................33
CEC 13.3.2 Feature Description ..............................................................................................33
CEC 13.3.3 Behavior with Earlier Versions .............................................................................35
CEC 13.4 One Touch Record .................................................................................................... 35
CEC 13.4.1 Messages .............................................................................................................35
CEC 13.4.2 Feature Description ..............................................................................................35
CEC 13.4.3 Behavior with Earlier Versions .............................................................................37
CEC 13.5 Timer Programming .................................................................................................. 37
CEC 13.5.1 Messages .............................................................................................................37
CEC 13.5.2 Feature Description ..............................................................................................38
CEC 13.5.3 Performing a Timed Recording using another device as source .........................39
CEC 13.5.4 Behavior with Earlier Versions .............................................................................39
CEC 13.6 System Information ................................................................................................... 39
CEC 13.6.1 Messages .............................................................................................................39
CEC 13.6.2 Feature Description ..............................................................................................40
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CEC 13.6.3
CEC 13.6.4
Version 1.4b
Additional Information...........................................................................................41
Behavior with Earlier Versions .............................................................................41
CEC 13.7 Deck Control .............................................................................................................. 41
CEC 13.7.1 Messages .............................................................................................................41
CEC 13.7.2 Feature Description ..............................................................................................42
CEC 13.7.3 Behavior with Earlier Versions .............................................................................42
CEC 13.8 Tuner Control............................................................................................................. 43
CEC 13.8.1 Messages .............................................................................................................43
CEC 13.8.2 Feature Description ..............................................................................................43
CEC 13.8.3 Behavior with Earlier Versions .............................................................................44
CEC 13.9 Vendor Specific Commands..................................................................................... 44
CEC 13.9.1 Messages .............................................................................................................44
CEC 13.9.2 Feature Description ..............................................................................................44
CEC 13.9.3 Behavior with Earlier Versions .............................................................................45
CEC 13.10 OSD Display ............................................................................................................... 45
CEC 13.10.1 Messages ...........................................................................................................45
CEC 13.10.2 Feature Description ............................................................................................46
CEC 13.10.3 Behavior with Earlier Versions ...........................................................................46
CEC 13.11 Device OSD Name Transfer ...................................................................................... 46
CEC 13.11.1 Messages ...........................................................................................................46
CEC 13.11.2 Feature Description ............................................................................................46
CEC 13.11.3 Behavior with Earlier Versions ...........................................................................47
CEC 13.12 Device Menu Control................................................................................................. 47
CEC 13.12.1 Messages ...........................................................................................................47
CEC 13.12.2 Feature Description ............................................................................................47
CEC 13.12.3 Behavior with Earlier Versions ...........................................................................48
CEC 13.13 Remote Control Pass Through................................................................................. 48
CEC 13.13.1 Messages ...........................................................................................................48
CEC 13.13.2 Feature Description ............................................................................................48
CEC 13.13.3 Press and Hold Operation..................................................................................49
CEC 13.13.4 RC Key Forwarding Recommendations.............................................................51
CEC 13.13.5 Other uses of <User Control Pressed> ..............................................................51
CEC 13.13.6 Deterministic UI Functions .................................................................................51
CEC 13.13.7 Non-Deterministic Commands with Parameters ................................................53
CEC 13.13.8 Behavior with Earlier Versions ...........................................................................53
CEC 13.14 Give Device Power Status ........................................................................................ 53
CEC 13.14.1 Messages ...........................................................................................................53
CEC 13.14.2 Feature Description ............................................................................................53
CEC 13.14.3 Behavior with Earlier Versions ...........................................................................54
CEC 13.15 System Audio Control............................................................................................... 55
CEC 13.15.1 Messages ...........................................................................................................55
CEC 13.15.2 Feature Description ............................................................................................55
CEC 13.15.3 Discovering the Amplifier’s Audio Format support .............................................60
CEC 13.15.4 Further behavior .................................................................................................61
CEC 13.15.4.1 Operation with legacy Amplifier .................................................................... 61
CEC 13.15.4.2 Operation with TVs that do not support the Feature..................................... 62
CEC 13.15.4.3 Audio-only use .............................................................................................. 62
CEC 13.15.4.4 Power State Changes ................................................................................... 62
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CEC 13.15.4.5 Usage of remote control pass through.......................................................... 62
CEC 13.15.5 Behavior with Earlier Versions ...........................................................................63
CEC 13.16 Audio Rate Control.................................................................................................... 63
CEC 13.16.1 Messages ...........................................................................................................63
CEC 13.16.2 Feature Description ............................................................................................63
CEC 13.16.3 Behavior with Earlier Versions ...........................................................................64
CEC 13.17 Audio Return Channel Control................................................................................. 64
CEC 13.17.1 Messages ...........................................................................................................64
CEC 13.17.2 Feature description.............................................................................................64
CEC 13.17.2.1 Initiation and Termination from ARC Rx device............................................ 65
CEC 13.17.2.2 Request from ARC Tx device ....................................................................... 66
CEC 13.17.3 Behavior with Earlier Versions ...........................................................................67
CEC 13.18 Capability Discovery and Control for HEC ............................................................. 67
CEC 13.18.1 Introduction and Messages ................................................................................67
CEC 13.18.2 CDC only Device ................................................................................................67
CEC 13.18.3 CDC Device with CEC........................................................................................67
CEC 13.18.4 Behavior with Earlier Versions ...........................................................................67
CEC 14 DEVICE STATES .........................................................................................................68
CEC 14.1.1 Device States .......................................................................................................68
CEC 14.1.2 State Changes......................................................................................................68
CEC 14.1.3 All Devices............................................................................................................68
CEC 14.1.4 TV .........................................................................................................................68
CEC 14.1.5 Recording Device .................................................................................................69
CEC 14.1.6 Playback Device...................................................................................................69
CEC 14.1.7 Menu Providing Device ........................................................................................70
CEC 15
MESSAGE DESCRIPTIONS........................................................................................71
CEC 16
MESSAGE DEPENDENCIES ......................................................................................97
CEC 17
OPERAND DESCRIPTIONS......................................................................................106
CEC APPENDIX A
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CEC Figures
Version 1.4b
CEC Page
CEC Figure 1 Example State Diagram ..................................................................................................... 5
CEC Figure 2 Example Message Flow Diagram ..................................................................................... 5
CEC Figure 3 Start bit pulse format showing minimum and maximum tolerances................................. 9
CEC Figure 4 Timing diagrams for both bit states.................................................................................. 10
CEC Figure 5 Timing Diagram for Follower Asserted Bit (Logical 0)..................................................... 11
CEC Figure 6 Block Structure ................................................................................................................. 12
CEC Figure 7 Header Block.................................................................................................................... 13
CEC Figure 8 Logical Address Allocation ............................................................................................... 21
CEC Figure 9 Examples of CEC systems with a “split architecture” TV ............................................... 22
CEC Figure 10 Example of the use of a second TV .............................................................................. 23
CEC Figure 11 A typical scenario illustrating the One Touch Play feature ............................................ 29
CEC Figure 12 Example message flow, when a CEC Switch is manually switched ............................ 33
CEC Figure 13 A typical scenario for the broadcast (system) Standby feature..................................... 34
CEC Figure 14 A typical scenario for the Standby feature to a specific device..................................... 34
CEC Figure 15 A typical scenario for the One Touch Record feature.................................................... 36
CEC Figure 16 A typical scenario for setting a Timer Record Block...................................................... 38
CEC Figure 17 Message exchange when getting the TV’s menu Language ....................................... 40
CEC Figure 18 A typical scenario when a menu language setting within the TV is modified............... 40
CEC Figure 19 A typical scenario for the Deck Control feature ............................................................. 42
CEC Figure 20 A typical scenario for selecting a new Service .............................................................. 43
CEC Figure 21 The messages sent in the Vendor Specific Commands feature .................................. 45
CEC Figure 22 A typical scenario where the user presses and quickly releases a key........................ 48
CEC Figure 23 A typical scenario where the user presses and holds a key......................................... 49
CEC Figure 24 Initiator Repetition Time, Follower Safety Timeout and Press and Hold behavior....... 50
CEC Figure 25 A typical scenario for to discover the power status of a target device.......................... 54
CEC Figure 26 A typical scenario for initiating the System Audio Control feature from a TV ............... 55
CEC Figure 27 A typical scenario for initiating the System Audio Control feature from an Amplifier.... 56
CEC Figure 28 A typical scenario for initiating the System Audio Control feature from a STB............. 57
CEC Figure 29 A typical scenario terminating the System Audio Control feature from a TV or STB... 57
CEC Figure 30 A typical scenario terminating the System Audio Control feature from the Amplifier ... 58
CEC Figure 31 Typical Operation of the volume control where the user presses and quickly releases a
key............................................................................................................................................................ 58
CEC Figure 32 An example of TV and Amplifier implementing Press and Hold behavior.................... 59
CEC Figure 33 An example of alternative connection link ..................................................................... 60
CEC Figure 34 Typical Operation to discover the Audio Format capability of an Amplifier .................. 61
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CEC Figure 35 An example of topology with ARC link........................................................................... 64
CEC Figure 36 Initiation and Termination from ARC Rx device............................................................. 65
CEC Figure 37 Request from ARC Tx device ........................................................................................ 66
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CEC Tables
Version 1.4b
CEC Page
CEC Table 1 CEC Electrical Specifications during the fully powered-Off state....................................... 7
CEC Table 2 CEC Electrical Specifications except during the fully powered-Off state ........................... 8
CEC Table 3 Frame Description ............................................................................................................. 12
CEC Table 4 Signal Free Time................................................................................................................ 17
CEC Table 5 Logical Addresses.............................................................................................................. 20
CEC Table 6 Deterministic UI Functions................................................................................................. 52
CEC Table 7 Non-deterministic UI commands with parameters............................................................ 53
CEC Table 8 Message Descriptions for the One Touch Play Feature................................................... 72
CEC Table 9 Message Descriptions for the Routing Control Feature ................................................... 73
CEC Table 10 Message Descriptions for the Standby Feature.............................................................. 75
CEC Table 11 Message Descriptions for the One Touch Record Feature ............................................ 76
CEC Table 12 Message Descriptions for the Timer Programming Feature .......................................... 77
CEC Table 13 Message Descriptions for the System Information Feature........................................... 79
CEC Table 14 Message Descriptions for the Deck Control Feature ..................................................... 81
CEC Table 15 Message Descriptions for the Tuner Control Feature .................................................... 83
CEC Table 16 Message Descriptions for the Vendor Specific Commands Feature ............................. 84
CEC Table 17 Message Descriptions for the OSD Display Feature...................................................... 86
CEC Table 18 Message Descriptions for the Device OSD Transfer Feature........................................ 87
CEC Table 19 Message Descriptions for the Device Menu Control Feature ........................................ 88
CEC Table 20 Message Descriptions for the Remote Control Passthrough Feature ........................... 89
CEC Table 21 Message Descriptions for the Power Status Feature ..................................................... 90
CEC Table 22 Message Descriptions for General Protocol messages ................................................. 91
CEC Table 23 Message Descriptions for the System Audio Control Feature ....................................... 92
CEC Table 24 Message Descriptions for the Audio Rate Control Feature............................................ 94
CEC Table 25 Message Descriptions for the Audio Return Channel Control Feature.......................... 95
CEC Table 26 Message Descriptions for the Capability Discovery and Control Feature ..................... 96
CEC Table 27 Message dependencies when receiving a message ..................................................... 98
CEC Table 28 Message dependencies when sending a message ..................................................... 102
CEC Table 29 Operand Descriptions.................................................................................................... 106
CEC Table 30 User Control Codes ....................................................................................................... 124
CEC Table 31 Broadcast System.......................................................................................................... 126
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CEC 1
Version 1.4b
Introduction
CEC is a protocol that provides high-level control functions between all of the various audiovisual products in
a user’s environment. This appendix describes the CEC protocol in the following order:
An overview of the recommended features available in CEC.
A Low Level Protocol Definition - Includes the electrical specification, signaling and bit timings and the
frame description.
A High Level Protocol Definition - Includes a detailed feature breakdown and individual message
descriptions.
CEC 1.1
Normative references
[1n] ISO 639.2 Code for the representation of names of languages - Part 2: Alpha 3 code
http://www.loc.gov/standards/iso639-2/langhome.html
CEC 1.2
Informative References
[1i] CENELEC, EN 50049-1:1997/A1:1998, Domestic and similar electronic equipment interconnection
requirements: Peritelevision connector
[2i] CENELEC, EN 50157, Domestic and similar electronic equipment interconnection requirements: AV.link
EN 50157-1 : Part 1
EN 50157-2-1 : Part 2-1
EN 50157-2-2 : Part 2-2
EN 50157-2-3 : Part 2-3
[3i] IEEE std. 1394-1995 HIGH PERFORMANCE SERIAL BUS section 8.3.2.5.1 – example use of
Company_id.
CEC 1.3
1.4b
1.4a
1.4
Document Revision History
Addition of operand for Version 1.4b to <CEC Version> (CEC 17)
Various editorial corrections throughout
Correction to operand of <Request Audio Descriptor> (CEC 13.15.3 and CEC 17)
Addition of operand for Version 1.4a to <CEC Version> (CEC 17)
Clarification that a Follower ignores a message when EOM is zero and no further Data
Blocks are received (CEC 6.1.1).
Recommendation to limit re-transmissions and clarification that frame re-transmission is
only used for ACK errors (CEC 7.1).
Clarification of the use of Logical Address 14; clarification of allocation of Logical
Addresses; clarification of “split architecture” and second TVs; addition of Device Type
“Pure CEC Switch” and “Video Processor” (CEC 10.2).
Clarification of what a CEC Switch is (CEC 11.1).
Addition of [Abort Reason] “Unable to Determine” and clarification of what the abort
reasons mean (CEC 12.3).
Better explanation of which messages are to be implemented and addition of references
to the Message Description, Message Dependency and Operand tables (CEC 13).
Clarification that an Active Source loses its Active Source status when there is an <Active
Source> message from another device (CEC 13.1.2).
Clarification that a device sends an <Active Source> message when it becomes the
Active Source; removal of recommendation that a source may pause when it loses
Active Source status (CEC 13.2.2).
Clarification of the difference between local and system standby (CEC 13.3.2).
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Version 1.4b
Clarification that a recording device may take several seconds before it can send an
accurate <Timer Status> or <Timer Cleared Status> message (CEC 13.5.2).
Allow Mobile devices and PCs not to change language if necessary; clarification that only
a TV can change language; recommendation that non-TV devices accept a mixture of
upper- and lower-case characters; CEC Version is no longer linked to HDMI Version;
(CEC 13.6.2 and CEC 13.6.3).
Clarification that a device needs to discover CEC Version if it wishes to send a <Vendor
Command> to a device from another vendor (CEC 13.9.2).
Better explanation of the [Display Control] parameter in OSD Display specifying how long
an OSD is displayed; clarification that Display Control “Clear Previous Message” does
not use any [OSD String] parameter (CEC 13.10.2).
Recommendation that an [OSD Name] of a device with multiple functionality refers to the
complete product (CEC 13.11.2).
Addition of detailed description for Press and Hold operation; definition and specification
of Initiator Repetition Time and Follower Safety Timeout; requirement to implement
Follower Safety Timeout in all Followers implementing RC Passthrough;
recommendation for Key Forwarding; clarification of other uses of <User Control
Pressed> message; clarification of the use of the non-deterministic “Power” [UI
Command]; addition of Select Broadcast Type and Select Sound Presentation nondeterministic UI commands with parameters (CEC 13.13.2 – CEC 13.13.7).
Clarification of operation, addition of missing items and corrections; addition of references
to Audio Return Channel; addition of method to discover Audio Format Support of an
Amplifier; addition of methods for ensuring the correct mute/unmute status of legacy
amplifiers; addition of operation with TVs that do not support the Feature; addition of
Audio-only use; clarification of behavior with Power State Changes; clarification of
usage of RC Passthrough with System Audio Control (CEC 13.15.2 – CEC 13.15.4).
Addition of new Audio Return Channel Control section (CEC 13.17).
Addition of Capability Discovery and Control section, referencing Supplement 2 for details
(CEC 13.18).
Clarification that “TV” refers to the device at Logical Address 0 in the message description
tables CEC Table 8 to CEC Table 26 ; clarification that CDC only devices shall not
implement messages in those tables.
Addition of new messages for Audio Return Channel and CDC in Tables CEC Table 25
and CEC Table 26 .
Corrections and updates to Message Dependency tables CEC Table 27 and CEC Table
28.
Additions and corrections to Operand Description table CEC Table 29.
Addition of UI commands for Media Top Menu, Media Context Sensitive Menu, Number
Entry Mode, Number 11, Number 12; clarification of notes to table (CEC Table 30).
Various editorial corrections throughout.
Clarification of pull-up resistance (for integrated implementations) and negative overshoot
on CEC line.
Clarification of when CEC Line Error Checking is applied.
Clarification of Signal Free Time values.
Re-naming of addresses STB to Tuner and DVD to Playback device.
Allocation of Tuner 4 and Playback Device 3 Logical Addresses from reserved set.
<Image View On> and <Text View On>: change to mandatory behavior with displayed
OSD/Menu
<Set Stream Path>: changes to mandatory behavior.
<Routing Change>: changes to mandatory behavior and addition of timing
recommendation.
Standby: clarification of behavior.
Extension of <Record On> to tuners and addition of Analogue and External sources.
Addition of new Error Codes for <Record Status>.
Addition of Timer Programming Feature (Analogue, digital and external).
Addition of Analogue Tuning <Select Analogue Service> to Tuner.
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High-Definition Multimedia Interface Specification
Version 1.4b
Addition of Major/Minor and 4-digit Virtual Channel Identification
Addition of <Get CEC Version> and <CEC Version>.
Change of some names for [Play Mode] and [Deck status] codes to better indicate
responses.
Allow <Vendor Command> to be shared between manufacturers in specific
circumstances.
Addition of <Vendor Command With ID> message, which may also be broadcast.
Inconsistent Feature naming now unified to “OSD Display”.
Clarification and addition of recommendation for a timeout for the User Commands.
RC passthrough: Addition of Pause-Record, Data, Power (On, Off and toggle);
clarification of <Root Menu>.
<Device Power Status> now made mandatory for an Initiator.
Addition of System Audio Control Feature.
Addition of Audio Rate Control Feature.
Updates to Message Dependencies and Operands tables as a result of above.
Correction to ASCII range.
Various editorial corrections throughout.
1.2a
Tolerance on internal pull-up resistance changed to ±5% in CEC Table 2.
Removal of test conditions from CEC Table 2,
Clarification of maximum message length.
Re-ordering of some Features in the text and splitting of message description table.
Update and clarification of mandatory and optional implementation status.
Clarification of rules with more explanations for Routing Control.
Additional examples and notes regarding the use of System Standby with recordings.
System Info simplified to language selection. <Set Language> now becomes <Set Menu
Language> with a simplified mechanism. Removal of <Set System Info Version
Number>, <Give System Info> and <Set Country>.
Removal of analogue tuning messages and addition of <Select Digital Service>.
Removal of Preset Download and Timer Programme Features.
Various editorial corrections throughout
1.2
Clarification of CEC line Standby behavior
Clarification of test conditions in CEC Table 2
Addition of CEC line pull-up using a current source
Addition of Give Power Status message
Clarification of response to <Abort> message
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CEC 2
Definitions
CEC 2.1
Conformance Levels
Version 1.4b
Because CEC is optional, the conformance level in this Supplement is only effective when the device
supports CEC. For example, the word "shall" indicates a mandatory requirement for the CEC supporting
devices. However, within the Features section (CEC 13) "shall" only indicates a requirement if the feature is
implemented.
CEC 2.2
Glossary of Terms
Audio System
A device, which is not a TV, that has the ability to render audio, e.g. an audio
Amplifier.
Broadcast Message
This is a message, sent to Logical Address 15, which all devices are expected to
receive.
Clear
Set to an empty/undefined state. When a Physical Address is cleared it takes the
value F.F.F.F. When a Logical Address is cleared it takes the value 15.
Deck
The part of a Recording Device or Playback Device that provides playback
functionality e.g. from a media such as DVD or Hard Disk.
Destination
The target device for a CEC message.
Follower
A device that has just received a CEC message and is required to respond to it.
Initiator
The device that is sending, or has just sent, a CEC message and, if appropriate, is
waiting for a Follower to respond.
Logical Address
A unique address assigned to each device (see section CEC 10.2)
Menu Providing Device A non-display device that may render a menu on TV.
Playback device
A device that has the ability to play media, e.g. a DVD Player.
Recording device
A device that has the ability to record a source such as an internal tuner or an
external connection.
Source Device
A device that is currently providing an AV stream via HDMI.
Tuner Device
A device that contains a tuner, e.g. an STB or a Recording Device.
Timer Setting Device
A device that has the ability to set the record timer blocks of a Recording Device.
TV
A device with HDMI input that has the ability to display the input HDMI signal.
Generally it has no HDMI output.
CEC 2.3
Usages and Conventions
CEC 2.3.1
State Diagrams
State diagrams describe behavior in terms of device states and events or actions. In these diagrams, the
ovals represent device states and the arrows represent events and/or actions that move the device from one
state to another state.
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Event (Condition)
State 2
State 1
Event / Action
CEC Figure 1 Example State Diagram
CEC 2.3.2
Message Flow Diagrams
Message Flow Diagrams show sequences of messages that occur between 2 devices.
Device 1
Device 2
User Interaction
Additional Information
<Message> [Parameter]
<Response> [Parameter]
CEC Figure 2 Example Message Flow Diagram
CEC 2.3.3
Notation
Within the CEC specification there are a number of notations:
<xxx> xxx is an opcode for a message, which is defined in section CEC 15
[yyy]
yyy is a data item, which is defined in section CEC 17.
“zzz”
zzz is a constant and is a possible value for a data item in section CEC 17.
N{….} indicates the item within the braces is repeated N times, this is used mainly in section CEC 17.
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CEC 3
Version 1.4b
Feature Overview
CEC provides a number of features designed to enhance the functionality and interoperability of devices
within an HDMI system. This section gives an overview of these features.
CEC 3.1
End-User Features
One Touch Play - Allows a device to be played and become the active source with a single button press.
System Standby - Enables the user to switch all devices to the Standby state with one button press.
One Touch Record - Offers a What You See Is What You Record (WYSIWYR) facility, meaning that
whatever is shown on the TV screen is recorded on a selected Recording Device.
Timer Programming – Allows the user to program the timers in a Recording Device from an EPG running on
a TV or STB.
Deck Control - Enables a device to control (e.g. play, fast forward etc.) and interrogate a Playback Device (a
deck).
Tuner Control - Allows a device to control the tuner of another device.
Device Menu Control - Enables a device to control the menu of another device by passing through user
interface commands.
Remote Control Pass Through - Enables remote control commands to be passed through to other devices
within the system.
System Audio Control – Allows an Audio Amplifier / Receiver to be used with the TV. The volume can be
controlled using any the remote controls of any suitably-equipped devices in the system.
CEC 3.2
Supporting Features
Device OSD Name Transfer - Enables devices to upload their preferred OSD name to the TV. The TV can
then use this name in any menus associated with that device.
Device Power Status – Allows the current power status of a device to be discovered.
OSD Display - Enables a device to use the on-screen display of the TV to display text strings.
Routing Control - Allows the control of CEC Switches for streaming of a new source device.
System Information - Queries the system to determine device addresses and language.
Vendor Specific Commands - Allows a set of vendor-defined commands to be used between devices of
that vendor.
Audio Rate Control – Allows an Amplifier to fractionally increase or decrease the playback rate of an audio
source.
Audio Return Channel Control – Controls the Audio Return Channel (ARC) part of the HDMI Ethernet and
Audio Return Channel (HEAC), which is fully specified in Supplement 2.
Capability Discovery and Control – Controls HDMI Ethernet Channel (HEC) part of HEAC, which is fully
specified in Supplement 2.
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CEC 4
Version 1.4b
Electrical Specification
The electrical specifications define CEC such that a maximum of 10 devices can interoperate in the worstcase scenario. In practice, many more may be expected to operate together as the worst case is highly
improbable.
A device that implements CEC protocols, as described in this CEC Supplement, and has enabled its CEC
functionality, shall:
Conform to Table 1 when it is powered-Off (e.g. power removed); or,
Conform to Table 2 in all other power states. In these states, the device shall keep monitoring the
CEC line for any messages addressing that device, including any messages that bring the device out
of Standby, see CEC 14.1.3.
During the powered-Off state (e.g. power removed), the CEC line is not monitored.
CEC Table 1 CEC Electrical Specifications during the fully powered-Off state
Description
Value
Leakage current in powered-Off state
1.8A max
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CEC Table 2 CEC Electrical Specifications except during the fully powered-Off state
Description
Value
Maximum Output Voltage Logic ‘0’
+0.6V
Minimum Output Voltage Logic ‘0’
0V
Maximum Output Voltage Logic ‘1’
+3.63 V
Minimum Output Voltage Logic ‘1’
2.5V
High to Low Input Voltage Threshold
Logic ‘0’
Vcecin(‘0’) ≥ +0.8V
Low to High Input Voltage Threshold
Logic ‘1’
Vcecin(‘1’) ≤ +2.0V
Typical Input hysteresis
+0.4 V
Maximum rise time (10% to 90%)
250 s
Maximum fall time (90% to 10%)
50 s
Internal device pull-up:
27k ohms ± 5% or
equivalent (e.g. a
current source); or
26k ohms ± 10%
when integrated.
Notes
3
2
The device shall remain within specification under the full-range of load conditions.
Notes:
1
This effectively requires that the internal pull-up circuit shall be disconnected from the CEC line when
the device is off. For example, this can be implemented by connecting an isolating diode between the CEC
input pin and the internal pull-up circuit, such that diode is reverse-biased in the off state with an external
device pulling-up the CEC line.
2
For information, input hysteresis is normally supplied by the microprocessor input circuit: in this
circumstance, external hysteresis circuitry is not needed.
3
During transition from Logic ‘1’ to Logic ‘0’ a negative overshoot with maximum 300mV and up to
150μs duration is allowed.
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CEC 5
Version 1.4b
Signaling and Bit Timings
All transactions on the CEC line consist of an Initiator and one or more Followers. The Initiator is responsible
for sending the message structure and the data. The Follower is the recipient of any data and is responsible
for setting any acknowledgement bits.
CEC 5.1
CEC Line Usage
A message is conveyed over the control signal line in a single frame; a frame is a self-contained unit
consisting of a start bit followed by a number of data bits.
An Initiator first has to test that the control signal line is free for use (described below). After that it generates
a high to low transition on the CEC line, followed by a series of pulses comprising data bits whose starting
point is defined by a high to low transition.
The Initiator provides bit timing and bit leading edges. Only one Initiator is allowed at any one time. A control
signal line arbitration mechanism avoids conflict when more than one Initiator begins transmitting at the same
time.
CEC 5.2
Bit Timing
CEC 5.2.1
Start Bit Timing
The pulse format of the start bit is shown in CEC Figure 3. It is unique and identifies the start of a frame.
The start bit has to be validated by its low duration (a) and its total duration (b).
b
High Impedance
a
Device Output
Low Impedance
3.5 ms
0 ms
3.9 ms
3.7 ms
4.3 ms
4.7 ms
4.5 ms
CEC Figure 3 Start bit pulse format showing minimum and maximum tolerances
CEC 5.2.2
Data Bit Timing
All remaining data bits in the frame, after the start bit, have consistent timing. There are, however, two types
of bits; an Initiator asserted bit and a Follower asserted bit. All bits apart from the acknowledge bit are
asserted by the Initiator. CEC Figure 4 shows both logical 1 and logical 0 timing diagrams for an Initiator
asserted bit.
The high to low transition at the end of a data bit is the start of the next data bit and only occurs if there is a
following data bit; after transmission of the final bit the CEC line remains high.
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High Impedance
Version 1.4b
Safe sample
period
Device Output
Logical 0
Low Impedance
1.5 ms
2.4ms
High Impedance
Device Output
Logical 1
L ow Impedance
0 ms
Ts
0.6 ms
T1
2.4 ms
T2 T3
T4 T5
T6
T7
T8
Nominal sample time 1.05 ms
TS
0 ms
The bit start event.
T1
0.4 ms
The earliest time for a low - high transition when indicating a logical 1.
T2
0.8 ms
The latest time for a low - high transition when indicating a logical 1.
T3
0.85 ms
The earliest time it is safe to sample the signal line to determine its state.
T4
1.25 ms
The latest time it is safe to sample the signal line to determine its state.
T5
1.3 ms
The earliest time a device is permitted return to a high impedance state (logical 0).
T6
1.7 ms
The latest time a device is permitted return to a high impedance state (logical 0).
T7
2.05 ms
The earliest time for the start of a following bit.
2.4ms
The nominal data bit period.
2.75 ms
The latest time for the start of a following bit.
T8
CEC Figure 4 Timing diagrams for both bit states
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CEC Figure 5 shows an example bit with both Initiator and Follower where the Follower may assert the bit to
a logical 0 to acknowledge a Data Block. The Initiator outputs a logical 1, thus allowing the Follower to
change the CEC state by pulling the control line low for the duration of the safe sample period.
High Impedance
Initiator Output
Low Impedance
0 ms
0.6 ms
2.4 ms
Safe sample
period
High Impedance
Follower Output
Low Impedance
1.5 ms
Ts
T1 T2
T3 T4
T5 T6
T7
T8
T9
TS
0 ms
The bit start event.
T1
0.35 ms
The latest response time for a Follower to go to the low impedance state.
T2
0.4 ms
The earliest the Initiator can return to high impedance when transmitting a logical 1.
T3
0.8 ms
The latest the Initiator can return to high impedance when transmitting a logical 1.
T4
0.85 ms
The earliest time at which the bit state on the CEC line is valid for reading.
T5
1.25 ms
The latest time at which the bit state on the CEC line is valid for reading.
T6
1.3 ms
The earliest time the Follower is permitted return to a high impedance state.
T7
1.7 ms
The latest time the Follower is permitted return to a high impedance state.
T8
2.05 ms
The earliest time for the start of a following bit.
2.4ms
The nominal data bit period.
2.75 ms
The latest time for the start of a following bit.
T9
CEC Figure 5 Timing Diagram for Follower Asserted Bit (Logical 0)
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CEC 6
Version 1.4b
Frame Description
The following table describes the complete CEC frame; the details of each block of the frame are given in the
subsequent sections.
CEC Table 3 Frame Description
Name
Description
Value
Start
Special start ‘bit’
N/A
Header Block
Source and Destination addresses (see CEC Figure 7)
See CEC Table 5
Data Block 1
(opcode block)
Opcode (optional)
See CEC Table 8
to CEC Table 26
Data Block 2
(operand blocks)
Operand(s) specific to opcode (optional, depending on
opcode)
See CEC Table
29
The maximum message size (Header Block plus opcode block plus operand blocks) is 16 * 10 bits
CEC 6.1
Header/Data Block description
All Data Blocks and Header Blocks are ten bits long and have the same basic structure, as shown in CEC
Figure 6.
Header/Data Block
7
6
5
4
3
2
1
Information bits
0
-
-
EOM
ACK
CEC Figure 6 Block Structure
The information bits are data, opcodes or addresses, dependent on context. The control bits, EOM and ACK,
are always present and always have the same usage.
CEC 6.1.1
EOM (End of Message)
The EOM bit is used to indicate if this is the final block in the message.
A ‘0’ bit specifies that one or more Data Blocks follow.
A ‘1’ bit specifies that the message is complete.
In the event that a message contains additional Data Blocks after an EOM is indicated, the Follower shall
ignore the additional blocks.
In the event that EOM is zero and no further Data Blocks are received, the Follower shall ignore the entire
message.
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CEC 6.1.2
Version 1.4b
ACK (Acknowledge)
The ACK bit is used by Follower(s) to acknowledge the data or Header Block. It is always set to 1 by the
Initiator. It operates in one of two modes:
For messages addressed to a single device:
A Follower that reads its own address in the Destination address field shall acknowledge with a ‘0’ ACK
bit.
All other devices shall not assert the ACK bit to logical ‘0’.
A ‘0’ read by the Initiator therefore indicates a successful transmission of the data or Header Block.
For broadcast messages the sense of the ACK bit is inverted to allow for a single device to reject a message:
All Followers that do not want to reject the message shall not assert the ACK bit to logical ‘0’.
A ‘1’ read by the Initiator therefore indicates that no device has rejected the data or Header Block – the
message transmission can therefore continue if required.
A Follower that wants to reject a broadcast message shall generate a ’0’ ACK bit.
A ‘0’ read by the Initiator therefore indicates that one or more devices have rejected the message.
CEC 6.1.3
Header Block Details
The Header Block consists of the source Logical Address field, the Destination Logical Address field, the end
of message bit (EOM) and the acknowledge bit (ACK) as shown in CEC Figure 7. The addresses for the
devices are specified in CEC Table 5.
Header Block
3
2
Initiator
1
0
3
2
1
Destination
0
-
-
EOM
ACK
CEC Figure 7 Header Block
The Initiator Logical Address field is used to identify the Initiator of the current frame. The Logical Address
of the Initiator is written in this field (see CEC 10.2). The field consists of bits one to four of the Header Block,
most significant bit first.
The Destination Logical Address field is used to identify the Destination of the current frame. The Logical
Address of the Destination is written in this field (see CEC 10.2). A special address (0b1111) is used for
broadcast messages. The field consists of bits five to eight of the Header Block, most significant bit first.
A message with the EOM bit set in the Header Block can be used to ‘ping’ other devices, to ascertain if they
are powered on. This is the <Polling Message> and the Initiator and Destination addresses will be different. It
is also used in 10.2.1 for allocating Logical Addresses: in this case the Initiator and Destination addresses are
the same.
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CEC 7
Version 1.4b
Reliable Communication Mechanisms
There are three mechanisms to provide a reliable communications medium for the transfer of frames:
Frame re-transmissions increase the chance of a successful message transfer.
Flow control ensures that communication only progresses as fast as the slowest Follower.
Frame validation.
Given these mechanisms and the active ACK method, a message transmitted and acknowledged should be
assumed correctly received. A message that does not result in a <Feature Abort> can be assumed to have
been acted upon. It is suggested that the Initiator device can assume this after 1 second.
CEC 7.1
Frame Re-transmissions
A valid frame is considered lost and therefore may be re-transmitted under the following conditions:
If a frame is not acknowledged in a directly addressed message.
If a frame is negatively acknowledged in a broadcast message.
If the Initiator detects low impedance on the CEC line when it is transmitting high impedance and is not
expecting a Follower asserted bit.
Re-transmission can be attempted up to 5 times for a single message and shall be attempted at least once.
The re-transmission shall be after a signal free time as described in CEC Table 4. If the re-transmission is as
a result of a <Polling Message> for a secondary task (see section CEC 12.2), then it is recommended to send
only one re-transmission.
The Re-transmission mechanism shall only be used for transport errors such as frame not ACK’d (i.e. it has
not been positively acknowledged or has been negatively acknowledged, according to message addressing,
see above). It shall not be used for application errors, e.g. in response to a <Feature Abort> or an incorrect or
unexpected application response - see section CEC 12.2, Protocol General Rules and section CEC 12.3,
Feature Abort.
CEC 7.2
Flow Control
To provide flow control, a receiving device may negatively acknowledge any data or Header Block it is at
present unable to process. A negative acknowledge will cause re-transmission by the Initiator.
CEC 7.3
Frame Validation
A Follower shall ignore a frame if the number of Data Blocks is less than the number specified for that opcode.
Note that for some CEC messages, the number of Data Blocks can vary.
CEC 7.4
CEC Line Error Handling
It is the responsibility of all devices acting as Followers to detect the existence of spurious pulses on the
control signal line and notify all other devices (primarily the Initiator) that a potential error has occurred.
An error is defined as a period between falling edges that is less than a minimum data bit period (i.e. too
short to be a valid bit). Note that the start bit has different timing from normal data bits and is used to identify
a valid CEC message. CEC Line Error checking shall start only after receiving a valid start bit.
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Errors are notified by the Follower generating a low bit period on the control signal line of 1.4-1.6 times the
nominal data bit period. After such an error notification the original Initiator should stop sending its current
frame and send a re-transmission later.
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CEC 8
Version 1.4b
Protocol Extensions
In order to allow for extensions to the protocol in future releases of the specification, the current opcodes and
parameters can be extended by adding further parameters onto them. If an older CEC node receives a
message with more operands than expected, it should ACK the additional operands and simply ignore them,
thus allowing extensions to already existing commands.
For entirely new commands, new opcodes can be allocated.
For entirely new device types, new addresses may be allocated.
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CEC 9
Version 1.4b
CEC Arbitration
Arbitration for the CEC line ensures collisions are spotted and a reliable message layer can be achieved.
All devices that want to transmit a frame onto the CEC line have to ensure that it has been inactive for the
signal free time, see CEC Table 4.
A device that has lost arbitration shall stop transmitting and become a Follower. The device shall then wait for
the CEC line to be inactive for the signal free time period as specified in CEC Table 4, before attempting to
send another message.
CEC line arbitration commences with the leading edge of the start bit and continues until the end of the
Initiator address bits within the Header Block. During this period the Initiator shall monitor the CEC line and if
whilst in high impedance state it detects low impedance then it shall assume that it has lost the arbitration to
a second Initiator.
It should be noted that this process gives priority to the Logical Address with the most leading zeros and,
ultimately, the TV.
CEC 9.1
Signal Free Time
Before attempting to transmit or re-transmit a frame, a device shall ensure that the CEC line has been
inactive for a number of bit periods. This signal free time is defined as the time since the start of the final bit of
the previous frame.
The length of the required signal free time depends on the current status of the control signal line and the
initiating device. The different signal free times required are summarized in the following table:
CEC Table 4 Signal Free Time
Precondition
Signal Free Time (nominal
data bit periods)
Present Initiator wants to send another frame immediately after its
previous frame
≥7
New Initiator wants to send a frame
≥5
Previous attempt to send frame unsuccessful
≥3
This means that there is an opportunity for other devices to gain access to the CEC line during the periods
mentioned above to send their own messages after the current device has finished sending its current
message.
CEC 9.2
Message Time Constraints
There are certain time constraints for messages that should be obeyed at application level. These are a
desired maximum response time of 200ms and a required maximum response time of 1 second.
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CEC 10
Version 1.4b
Device Connectivity and Addressing
CEC is a protocol based on a bus system and therefore cannot alone ascertain the physical connectivity of
the network. The mechanism defined in section 8.7 uses DDC to allocate Physical Addresses to devices in
the network.
All CEC devices therefore have both a physical and Logical Address, whereas non-CEC devices only have a
Physical Address.
CEC 10.1
Physical Address Discovery
The algorithm defined in 8.7.3 is used to allocate the Physical Address of each device.
Whenever a new Physical Address (other than F.F.F.F) is discovered, a CEC device shall:
allocate the Logical Address (see CEC 10.2.1)
report the association between its logical and Physical Addresses by broadcasting <Report Physical
Address>.
This process allows any node to create a map of physical connections to Logical Addresses.
CEC 10.2
Logical Addressing
Each device appearing on the control signal line has a Logical Address which is allocated to only one device
in the system (except for devices using Logical Address 15, where several devices may take this address
with reduced functionality). Except for Logical Addresses 14 and 15, the Logical Address defines a device
type as well as being a unique identifier. These are specified in CEC Table 5.
A device shall advertise a function with a Logical Address, such as a Tuner, only if it supports at least the
mandatory messages for that function as indicated in CEC Table 8 to CEC Table 26. If a physical device
contains the mandatory functions of more than one device type then it should take the Logical Addresses for
each of those device types. For example, if a DVD recorder has a tuner, it may take one of the addresses 3,
6, 7 or 10 (Tuner) in addition to one of 1, 2 or 9 (Recording Device). A home theater system (e.g. DVD Player
with integrated Amplifier) may take one of the addresses 4, 8 or 11 (Playback Device) in addition to address 5
(Amplifier).
If a device wants to advertise Amplifier functionality, it shall try to allocate the relevant ‘Audio System’ (5)
Logical Address;
If a device wants to advertise TV functionality and has Physical Address 0.0.0.0, it shall try to allocate
the relevant ‘TV’ (0) Logical Address. If the 'TV'(0) Logical Address cannot be allocated it may try to
allocate the 'Specific Use' (14) Logical Address (note that allocating the 'Specific Use' (14) Logical
Address might result in reduced functionality being available);
A TV at a Physical Address other than 0.0.0.0 shall try to allocate the ‘Specific Use’ (14) address. If
address 14 is already allocated it shall take the ‘Unregistered’ Logical Address (15).
Else if the device can become an Active Source, then:
If it wants to advertise recording functionality (that can be controlled via CEC), it shall try to allocate
one of the ‘Recording device’ Logical Addresses;
If it wants to advertise tuning functionality (that can be controlled via CEC), it shall try to allocate one
of the ‘Tuner’ Logical Addresses;
Otherwise, it shall try to allocate one of the "Playback device" addresses;
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Version 1.4b
For a Special Device (see CEC 10.2.2) using a single CEC line (see CEC Figure 9A and CEC Figure
10A), or for the output (secondary CEC Line side) of a Special Device which has both primary and
secondary CEC lines (see CEC Figure 9B and CEC Figure 10B):
If it wants to advertise being a second TV, then it shall try to allocate ‘Specific Use’ (14) Logical
Address. Such a device uses “TV” for [Device Type] when sending a <Report Physical Address>
message;
If it wants to advertise being a Video Processor (see CEC Table 29), then it shall try to allocate
‘Specific Use’ (14) Logical Address. Such a device uses “Video Processor” for [Device Type] when
sending a <Report Physical Address> message;
Else if it wants to advertise any other functionality in the special device, such as a Tuner, it shall try to
allocate a Logical Address for each device type that it wishes to advertise.
For a “Special Device” which has both primary and secondary CEC lines the input (primary CEC line)
side shall try to allocate the relevant ‘TV’ (0) Logical Address.
If a device is a pure CEC Switch or CDC-only device according to Supplement 2 or it does not want to
advertise any functionality, it shall take the ‘Unregistered’ Logical Address (15).
‘Specific Use’ Logical Addresses (14) shall only be used for those cases described above.
It is allowed for a device to declare the functionality of another device type by using a different Logical
Address. For example a recordable DVD device may take the address 4, 8 or 11 to expose only the
functionality of a standard DVD ‘Playback Device’. In this case, the recording functionality will not be available
or controllable via CEC.
A Recording Device with addresses 1,2 or 9 (‘Recording Device’) shall not also take a ‘Playback Device’
Logical Address as the playback functionality is also included in the recorder functionality.
If a device has multiple instances of a particular functionality, it should advertise only one instance. For
instance, if a device has multiple tuners, it should only expose one for control via CEC. In this case, it is up to
the device itself to manage multiple tuners.
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CEC Table 5 Logical Addresses
Address
Device
0
TV
1
Recording Device 1
2
Recording Device 2
3
Tuner 1
4
Playback Device 1
5
Audio System
6
Tuner 2
7
Tuner 3
8
Playback Device 2
9
Recording Device 3
10
Tuner 4
11
Playback Device 3
12
Reserved
13
Reserved
14
Specific Use
15
Unregistered (as Initiator address)
Broadcast (as Destination address)
CEC 10.2.1
Logical Address Allocation
Note that a Logical Address should only be allocated when a device has a valid Physical Address (i.e. not
F.F.F.F), at all other times a device should take the ‘Unregistered’ Logical Address (15).
Reserved addresses shall not be used at present and are reserved for future extensions to this specification.
Where more than one possible Logical Address is available for the given device type (e.g. ‘Tuner 1’, ‘Tuner 2’,
etc.), an address allocation procedure shall be carried out by a newly connected device. The device takes the
first allocated address for that device type and sends a <Polling Message> to the same address (e.g. ‘Tuner
1’ ‘Tuner 1’). If the <Polling Message> is not acknowledged, then the device stops the procedure and
retains that address.
If the first address is acknowledged, then the device takes the next address for that device type and repeats
the process (e.g. ‘Tuner 2’ ‘Tuner 2’). Again, if the message is not acknowledged, the device keeps that
address.
This procedure continues until all possible ‘type specific’ Logical Addresses have been checked; if no ‘type
specific’ Logical Addresses are available the device should take the unregistered address (15). Note that
several physical devices might be sharing this address.
A device may lose its Logical Address when it is disconnected or switched off. However, it may remember its
previous Logical Address, so that the next time it is reconnected or switched on, it can begin the polling
process at its previous Logical Address and try each other allowable Logical Address in sequence before
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taking the unregistered address. For example if an STB that was previously allocated address ‘Tuner 2’ is
reconnected, it would poll ‘Tuner 2’, ‘Tuner 3’, ‘Tuner 4’ and ‘Tuner 1’ before taking the unregistered address.
If a device loses its Physical Address at any time (e.g. it is unplugged) then its Logical Address should be set
to ‘Unregistered’ (15).
No Physical
Address
Assigned physical address /
send polling message to first
device type address
Physical Address lost
First Device type
Address
no acknowledgement
bus busy – message failed /
send polling message to first device type address
Awaiting
First address
acknowledgement
acknowledgement /
send polling message to second device type address
bus busy message failed /
send polling message to second
device type address
Higher Device
type Address
no acknowledgement
Awaiting
higher Address
acknowledgement
acknowledgement (more addresses to test) /
send polling message to next higher address
of device type
Unregistered
Device Address
acknowledgement (all addresses of device type tested)
CEC Figure 8 Logical Address Allocation
CEC 10.2.2
Special Devices
Some implementations, for instance a TV, may be implemented using “split architecture”, i.e. as two
physically separate boxes consisting of the display device itself (such as an LCD panel) which is connected
using HDMI and CEC to an associated Video Processor (also called control box or media receiver), which
carries the HDMI inputs. The display (panel) takes Logical Address ‘TV’ (0).
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Display
Camcorder
PA = 1.0.0.0
LA = See text
Video
Processor
PA = 1.1.0.0
LA = Audio System Amplifier
PA = 2.0.0.0
LA = Recording
Device 1
STB PA = 1.2.0.0
LA = Tuner 1
Secondary CEC Line
PA = 0.0.0.0
LA = TV (0)
= HDMI TMDS lines
= Primary (or single) CEC Line
= Secondary CEC Line
Note: actual Physical and Logical addresses will
depend on topology and devices present in the system.
Primary CEC Line
PA = Physical Address
LA = Logical Address
Version 1.4b
PA = 1.1.1.0
LA = Playback DVD
Device 1
PA = 0.0.0.0
LA = TV (0) on
secondary CEC line
Display
Camcorder
PA = 1.0.0.0
LA = See text
PA = 0.0.0.0
LA = TV (0) on
primary CEC line
No CEC communication
with primary CEC line
Video
Processor
PA = 1.0.0.0
LA = Audio Amplifier
System
STB
PA = 2.0.0.0
LA = Tuner 1
PA = 1.1.0.0
LA = Playback DVD
Device 1
A. Using a single CEC line
B. Using Primary and Secondary CEC lines
CEC Figure 9 Examples of CEC systems with a “split architecture” TV
In CEC Figure 9A, the CEC line is connected between the panel and the Video Processor using a single CEC
line. A device directly connected to the panel (such as the camcorder in the example) can use CEC. If the
Video Processor has other functionality (e.g. a Tuner) that is available for control via CEC, then it tries to take
a Logical Address for that functionality. If it has no other such functionality, it takes the ‘Unregistered’ Logical
Address (15), or tries to take the ‘Specific Use’ Logical Address (14) if it needs direct addressing – see CEC
10.2 for full details.
It is also possible to connect the display to the Video Processor using a secondary CEC line that is
completely independent of the primary CEC line, i.e. the two CEC lines are not physically connected in the
Video Processor, see CEC Figure 9B and section 4.2.10 of the HDMI specification. The primary CEC line is
used to connect the Video Processor to all other HDMI devices. In this case also, the display panel takes
Physical Address 0.0.0.0 and Logical Address 0 on the secondary CEC line. On the secondary CEC line the
Video Processor is allocated Physical Address 1.0.0.0. If it has other functionality that is available for control
via CEC on the secondary CEC line (e.g. a Tuner), it tries to take a Logical Address for that functionality. If it
has no other functionality, it takes the ‘Unregistered’ Logical Address (15), or tries to take the ‘Specific Use’
Logical Address (14) if it needs direct addressing – see CEC 10.2 for full details. On the primary CEC line
(connected to the other HDMI devices) the Video Processor takes Physical Address 0.0.0.0 with Logical
Address ‘TV’ (0). Note that in this situation, it is not possible for any device connected using the secondary
CEC line directly to the display to have CEC communications with devices using the primary CEC line.
CEC Figure 10 below shows how a second TV can be used. In both these examples, the second TV may
take the Specific Use Logical Address (14) and/or the Logical Address of any other functionality in the TV,
such as a Tuner – see CEC 10.2 for full details. In the example with both primary and secondary CEC lines,
the second TV takes these addresses on the secondary CEC Line.
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Camcorder
PA = 1.0.0.0
LA = see text
PA = 1.1.0.0
LA = Audio System
PA = 1.1.1.0
LA = Playback
Device 1
Second
TV
Amplifier
PA = 2.0.0.0
LA = Recording
Device 1
STB PA = 1.2.0.0
LA = Tuner 1
Primary CEC Line
Main TV
PA = 0.0.0.0
LA = TV (0)
Version 1.4b
Secondary CEC Line
High-Definition Multimedia Interface Specification
Main TV
PA = 0.0.0.0
LA = TV (0) on
secondary CEC line
PA = 1.0.0.0
LA = see text
PA = 0.0.0.0
LA = TV (0) on
primary CEC line
Camcorder
No CEC communication
with primary CEC line
Second
TV
PA = 1.0.0.0
LA = Audio Amplifier
System
STB
PA = 2.0.0.0
LA = Tuner 1
PA = 1.1.0.0
LA = Playback DVD
Device 1
DVD
CEC Figure 10 Example of the use of a second TV
CEC 10.2.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.4.
Version 1.4 allows the use of Logical Address ‘Specific Use’ (14) for devices which are not additional TVs and
which also need direct addressing. Such use was not mentioned in Versions 1.3a and earlier and behavior
with these devices is undefined.
Version 1.4 adds new values of “Video Processor” and “Pure CEC Switch” to [Device Type], see CEC Table
29. Behavior with devices conforming to Versions 1.3a and earlier is undefined.
Version 1.3a added new Logical Addresses of ‘Tuner 4’ and ‘Playback Device 3’: these will not be recognized
by devices conforming to CEC specifications before Version 1.3a.
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CEC 11
Version 1.4b
Switch Requirements
One of the major uses of the Physical Address identification is to allow a Switch to be controlled in order to
enable a specific device to stream to the TV.
All Switches consist of a single switched TMDS connection, and a fully wired CEC connection to each source
device. Although the TMDS connections are switched, the CEC line itself is not changed since all CEC lines
are connected together internally in the device, see HDMI specification section 4.2.10.
A CEC Switch can interpret and send CEC messages and can be switched by CEC messages.
The use of non-CEC Switches is deprecated. These do not interpret nor send CEC messages and cannot be
switched by CEC messages. Non-CEC Switches stop the correct operation of many CEC Features including
mandatory Features such as One Touch Play. They also prevent other CEC-compliant devices from
operating correctly. Further information on non-CEC Switches can be found in CEC Appendix A.
CEC 11.1
CEC Switch
A CEC Switch allocates a unique child_address for every connection below the CEC Switch, i.e. it allocates
the address for devices connected to the inputs of the CEC Switch. This means that any device connected to
the CEC Switch will always have a valid Physical Address (assuming the CEC Switch itself has a valid
Physical Address). Therefore, any device below the CEC Switch may take a Logical Address and can react to
CEC messages in a normal way. The CEC Switch is effectively transparent and will enable all standard CEC
communications in its connected source devices.
A CEC Switch is defined as a device that has its own Physical Address, sends CEC messages and is
controlled by receiving/monitoring CEC messages and has:
only one HDMI input and has no internal sources and no non-HDMI inputs. This device has one HDMI
output and e.g. is a Repeater or does video processing from input to output; or
two or more HDMI inputs and can select between one of those inputs for HDMI output or rendering; or
one or more HDMI inputs and can select between one of those HDMI inputs and some non-HDMI inputs
or internal sources, for HDMI output or rendering. For example, the device may have, in addition to an
HDMI input, a number of non-HDMI inputs, such as SPDIF, or an internal source such as a tuner or
playback device. In this example, the CEC Switch can select between an HDMI input, an external SPDIF
input, or an internal tuner or playback device, for HDMI output or rendering.
If a device does not have a Physical Address, then it is not a CEC Switch.
For further details of behavior and implementation for CEC Switches (as defined above), see CEC 13.2,
Routing Control.
A CEC Switch can be part of another device, such as a TV or Amplifier. A device implementing CEC Switch
functionality with such other functionality shall provide its advertised functionality (e.g. TV or Audio System) in
addition to its CEC Switch functionality. In these cases, the CEC Switch takes the relevant address of its
advertised functionality, i.e. 0 (‘TV’) or 5 (Audio System). The power control for the CEC Switch functionality
should be separate from the power control for the other functionality so that the CEC Switch can be active
even when the main functionality is in Standby – see CEC 13.2.2 for more details.
A device that is a “pure” CEC Switch and has no other functionality uses the ‘Unregistered’ Logical Address
(15) for communications.
For CEC Switches, there is a requirement to react on <Active Source> and <Set Stream Path> messages.
Both of these messages require the CEC Switch to change to the source device according to the physical AV
stream path indicated by the CEC message. These mechanisms allow a source device to configure the CEC
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Switches between itself and the TV to ensure that its output is displayed, or for the TV to specifically receive
the output from a given device.
It is possible that a user may change a CEC Switch manually. In this instance a CEC Switch shall send a
<Routing Change> message to inform other devices about the change –see section CEC 13.2.2.
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CEC 12
Version 1.4b
High Level Protocol
As described in the previous sections, messages consist of an opcode and a number of parameters. This is
the high level protocol.
This protocol can be described best by detailing the messages and the data types used for the parameters.
These are detailed in CEC Table 8 to CEC Table 26.
Although these tables explain the majority of the high level protocol, there are some special situations that
require further explanation. These are given in the following sections.
CEC 12.1
Source Declaration
For a device to act as a Source Device, it shall issue an <Active Source> message to declare its intention.
Thus any presently active source shall act appropriately.
CEC 12.2
Protocol General Rules
A message that is defined as being valid only when directly addressed shall be ignored if received as a
broadcast message.
A message that is defined as being valid only when broadcast shall be ignored if received as a directly
addressed message.
All numbers greater than one byte are transmitted as bytes in big endian format.
All bit sequences are sent most significant bit first.
A Follower shall respond to a message coming from any valid Logical Address from 0 to 14 unless otherwise
stated.
A Follower shall ignore a message coming from address 15 (unregistered), unless:
that message invokes a broadcast response (e.g. <Get Menu Language>); or
the message has been sent by a CEC Switch (a <Routing Change> or <Routing Information>
message); or
the message is <Standby>; or
the message is a <Report Physical Address> or an <Active Source> (if the Follower wants to use); or
the message is a CDC message that the Follower supports.
If a message was successfully received (i.e. was correctly ACK'd) but failed at the application level (e.g.
<Feature Abort> or an incorrect or unexpected response), then the Initiator should limit the number of times it
sends the same message (e.g. while waiting for a particular application state of the Follower).
If a <Polling Message> has not been ACK’d, the device is not present or is not in a state to respond, then
repeated polling of these addresses should be limited.
If a device wishes to send a <Polling Message> for a secondary or background task, it should not disturb any
primary or main tasks such as those tasks which have been initiated by the user. In this case such a
secondary or background <Polling Message> (which is not the direct result of a user-initiated action or
Logical Address allocation) should not be sent more frequently than once every 500ms.
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If such a secondary <Polling Message> is not ACK’d, then the Initiator may send re-transmissions according
to section CEC 7.1. In this case, it is recommended not to send more than one re-transmission.
For messages that return a response:
Initiators should not rely on answers coming back in the same order as the requests that were sent
out;
Response messages might be interleaved with other messages initiated by the addressed device, or
other devices;
sending the same opcode (or the same vendor command contained in a <Vendor Command> or
<Vendor Command with ID> message) to the same device more than once without first waiting for
the reply may cause problems.
CEC 12.3
Feature Abort
All devices shall support the message <Feature Abort>. It is used to allow devices to indicate if they do not
support an opcode that has been sent to them, if it is unable to deal with the message at present, or if there
was something wrong with the transmitted frame at the high-level protocol layer.
<Feature Abort> has two parameters, the opcode and a reason for its rejection of the frame.
The reasons for rejection are indicated in the [Abort Reason] Operand, which are specified in the individual
Feature descriptions (see CEC 13). If no [Abort Reason] is specified in those sections, devices may use the
following values to indicate the reason for rejection:
“Unrecognized opcode”:
the device never recognizes or supports that opcode.
“Not in correct mode to respond”: the device recognizes and supports the opcode and any operands, but
cannot perform that action in its current application mode. Some
examples are:
- the device supports a message when it is in the active state, but not
during the Standby state;
- it is currently recording.
“Cannot provide source”:
the device recognizes and supports the opcode and any operands, but
cannot provide the source signal.
“Invalid operand”:
the device recognizes and supports the opcode, but does not recognize or
support the operand.
“Refused”:
the device recognizes and supports the opcode and operands, but is
prevented from taking that action because of some other rules, such as
copy protection or parental lock. Note that messages like <Record
Status> provide more comprehensive information, whereas a <Feature
Abort> "Refused" can be used in response to a Remote Control
Passthrough command e.g. for recording.
“Unable to determine”
the device is in a state, such as Standby, where it cannot determine if the
opcode or operands are supported by the device.
Note that if the device is in the Standby state it might not be able to respond with an accurate [Abort Reason]
because full information may only be available when the device is active.
Note: Devices implementing Versions 1.3a or earlier will not respond with the “Unable to determine” code and
are likely to respond with a “Not in correct mode to respond” code.The reaction to a faulty message by the
Follower depends on whether the message was directed or broadcast:
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For a broadcast message:
A Follower that receives a broadcast message which it does not support, ignores the received message,
and does not send a <Feature Abort>.
For a directly addressed message:
<Feature Abort> is used as a response to any failure.
If the <Feature Abort> [Abort Reason] was “Unrecognized opcode”, the Initiator should not send the same
message to the same Follower again at that time to avoid saturating the bus. .
If the [Abort Reason] was other than “Unrecognized opcode”, the Initiator may send the message again. It is
recommended that it waits for at least 200ms in order to allow time for the Follower to recover from the state
that caused the initial <Feature Abort> message.
<Feature Abort> is also used as a response to the <Abort> message during testing, see CEC 12.4
CEC 12.4
Abort
The <Abort> message shall be implemented as a Follower in all devices except pure CEC Switches and is
used during testing only. It shall be directly addressed to a specific device, which shall respond with a
<Feature Abort> message. In this instance, any valid [Abort Reason] operand may be returned.
A device shall ignore an <Abort> message which is broadcast.
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CEC 13
Version 1.4b
CEC Features Description
This section describes the message transfer and additional details for a number of common features enabled
by CEC. Note that where a feature is supported, all messages within that feature should be implemented.
Details of which messages are mandatory for each Feature are shown in CEC Table 8 to CEC Table 26. The
support for some messages depends on which other messages are supported – for details see CEC Table 27
and CEC Table 28. Details of Operands for use with the messages are shown in CEC Table 29.
CEC 13.1
One Touch Play
CEC 13.1.1
Messages
The following messages are used for the One Touch Play feature:
<Active Source>, <Image View On>, <Text View On>
For details of which messages are mandatory, see CEC Table 8, CEC Table 27 and CEC Table 28.
CEC 13.1.2
Feature Description
The One Touch Play feature allows a device to be played and become the active source with a single button
press.
A device shall send the message <Image View On> to the TV only when it needs to indicate that its output
should be displayed on the screen. If the TV is in a Text Display state (e.g. Teletext) it should switch to the
Image Display state. If a menu is being displayed on the TV it should remain on screen.
A device may alternatively send the message <Text View On>. This message has the same functionality as
<Image View On> with the addition that any menus that the TV is displaying should be removed.
Playback
Device
TV
User presses Play
<Image View On>
broadcast to all
devices including TV
<Active Source>
If Required:
TV powers on;
TV enters the Image
Display state
Switches to
relevant HDMI
connector
CEC Figure 11 A typical scenario illustrating the One Touch Play feature
When a source needs to display its output on the TV, it should send an <Image View On> message
whenever it sends an <Active Source> message, as the source is not aware of the current Standby status of
the TV.
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The source shall send the associated <Active Source> message only when it has some stable video for
display to the user.
If the TV is brought out of the Standby state by an <Image View On> message, it should buffer <Active
Source> messages received while it is powering up so that it may select the correct input (if necessary). If
this is not possible, or none were received, then it should enquire which device is the active source by
sending a <Request Active Source> message.
Whenever a device becomes the new active source it shall broadcast an <Active Source> message. The
currently active source shall lose its active source status on receiving an <Active Source> message from
another device.
Note: there is a special case when a TV switches to its internal tuner or to another non-HDMI source (e.g.
Y/C, or a SCART socket on European market sets). In this case, it is the TV which broadcasts the
<Active Source> message with address 0.0.0.0.
Note that it is mandatory for a source to implement at least one of <Image View On> or <Text View On>.
CEC 13.1.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
When sending this Message
From Version 1.3 or
earlier Device
To Version 1.3a or
later Device
Possible behavior
<Image View On>
Any source
TV
The TV might not keep its current
menu on the screen
<Text View On>
Any source
TV
The TV might not remove its current
menu on the screen
<Active Source>
Any source
Any
The use of <Active Source> by
devices before 1.3a was
recommended, not mandatory.
CEC 13.2
Routing Control
CEC 13.2.1
Messages
The following messages are used for the Routing Control feature:
<Active Source>, <Inactive Source>, <Request Active Source>, <Set Stream Path>, <Routing Change>,
<Routing Information>
For details of which messages are mandatory, see CEC Table 9, CEC Table 27 and CEC Table 28.
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CEC 13.2.2
Version 1.4b
Feature Description
This feature is used to control the routing of the HDMI network, by controlling CEC Switches. In general
whenever a device starts being streamed to the TV it shall send an <Active Source> message (see OneTouch Play in section CEC 13.1).
On receiving an <Active Source> message, CEC Switches between the device and the TV shall become
active (if necessary) and switch (if required) to ensure that there is an active path from the device at the
Physical Address specified to the TV. CEC Switches shall not send a <Routing Change> message in this
case. Devices which have other functionality and which also incorporate a CEC Switch, such as an Amplifier
with several HDMI inputs, need only bring the CEC Switch part out of the Standby state as a response to the
<Active Source> message, leaving the other functionality (e.g. Amplifier) still in the Standby state.
Whenever a device becomes the new active source it shall broadcast an <Active Source> message. The
currently active source shall lose its active source status on receiving an <Active Source> message from
another device.
When a device comes out of the Standby state or a (mains) off state, it may broadcast a <Request Active
Source> message to discover if any other device is currently acting as the active source, see One Touch Play
in section CEC 13.1. On receiving a <Request Active Source> message, the active source device shall
respond by broadcasting an <Active Source> message. A particular instance of this rule is when a TV comes
out of the Standby state some time after its source device(s). In this case it might not know the currently
active source and it might not know which is the relevant connector to use (if the TV has multiple HDMI
connectors), because it was in the Standby state or powering up when the device sent its <Active Source>
message. Here, the <Request Active Source> message and the corresponding <Active Source> response
are used to identify the relevant connector.
When the System Audio Control feature is started by an Amplifier (e.g. as a result of a local user command
on the Amplifier), the <Request Active Source> message shall be sent by the Amplifier to discover the
currently active source in order present the relevant sound for the video (see CEC 13.15). This is not
necessary when the System Audio Control feature is not active.
The user may select a device to view via the TV user interface. In contrast to the <Active Source> message
(which is sent by the current active source to the TV), the <Set Stream Path> is sent by the TV to the source
device to request it to broadcast its path using an <Active Source> message. In this case, the TV should
broadcast a <Set Stream Path> message with the Physical Address of the device it wants to display as a
parameter. Any CEC Switches between the device and TV shall switch (if required) to ensure the device is on
the active AV path. CEC Switches shall not send a <Routing Change> message in this case. This feature
also ensures that non-CEC-compliant devices in the network can be switched to, if for instance they have
been manually set up in the TV menu. A CEC device at the location specified by the <Set Stream Path>
message should come out of the Standby state (if necessary). If and when it has stable video to display, it
shall broadcast an <Active Source> message and begin streaming its output.
Note: there is a special case when a TV switches to its internal tuner or to another non-HDMI source (e.g.
Y/C, or a SCART socket on European market sets). In this case, it is the TV which broadcasts the
<Active Source> message with address 0.0.0.0.
When the user has specifically sent the currently active device only to the Standby state (e.g. as the result of
a user action using the device’s local control, such as its own remote controller), it should send an
<Inactive Source> message with its own Physical Address as an operand. It is a manufacturer decision to
decide the TV’s response: it may, for example, display its own internal tuner, or select another device for
display. In these cases, the TV should send a new <Active Source> message with its own Physical Address
(0.0.0.0, when displaying its own internal tuner), or send a <Set Stream Path> to a new device for display.
Note that an <Inactive Source> message can also be sent when the Source Device has no video to be
presented to the user, even if the device is not in the Standby state.
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The user may manually change a CEC Switch. When the user switches a CEC Switch:
from one HDMI input to another HDMI input, it shall broadcast a <Routing Change> message. This will
inform all devices in the network that the current active route below the CEC Switch has changed. The
device that has been deselected by a CEC Switch loses its Active Source status.
from an HDMI source to a non-HDMI source (e.g. to an internal tuner in the TV or Amplifier; or external
SPDIF input on an Amplifier), then it should not send a <Routing Change> message.
if the CEC Switch wants to present stable video (which is originating from that non-HDMI source) via
HDMI to the user and wants to act as a new Active Source, the CEC Switch shall broadcast an <Active
Source> message with its own Physical Address.
if the TV is changed to its internal tuner or an external non-HDMI input connected directly to the TV, it
shall broadcast an <Active Source> message with its own Physical Address.
from a non-HDMI (or internal) source to an HDMI input, then the device should send a <Routing
Change> message to determine the HDMI path below the CEC Switch.
If a CEC Switch is at the new position indicated by the <Routing Change> message then it shall broadcast a
<Routing Information> message with the Physical Address of its current active path. If a CEC Switch at the
new position receives a <Routing Information> message then it shall broadcast a <Routing Information>
message to indicate its current active path. In this way the all CEC Switches are aware of the route to the
new source and the last <Routing Information> message contains the complete route (address) to the new
source.
If a CEC Switch has non-HDMI inputs and the currently selected input is a non-HDMI source, the CEC Switch
should not send a <Routing Information> message in response to a <Routing Change> or <Routing
Information> message. For example, if the CEC Switch is already using an analogue input, then the CEC
Switch should not send a <Routing Information> message in response to a <Routing Change> or <Routing
Information> message.
A TV (when it is the Root Device at Physical Address 0.0.0.0) does not implement the <Routing Information>
message as an Initiator.
Optionally, if the TV detects that the active source device has been de-selected by changing the Switch it
may either switch to an internal service or may send a <Set Stream Path> message to the device at the new
location to indicate that it should become the new active source. In this case, the TV shall wait for a minimum
of 7 nominal data bit periods and a recommended maximum of 500ms before reacting to a <Routing
Change> or <Routing Information> message to allow CEC Switches to relay any <Routing Information>
messages that are required.
The following diagram shows an example of the message flow when a user manually switches a CEC Switch.
(CEC Switches are shown filled).
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0.0.0.0
Switched Manually
1.0.0.0
1.1.0.0
<Routing Information> [1.2.1.1]
<Routing Change> [1.1.0.0] [1.2.0.0]
<Routing Information> [1.2.1.0]
1.2.0.0
1.2.1.0
1.2.1.1
1.2.2.0
1.2.1.2
CEC Figure 12 Example message flow, when a CEC Switch is manually switched
CEC 13.2.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
Some CEC Switches and TVs conforming to Version 1.3a or earlier might send a <Routing Change>
message when they receive <Active Source> or <Set Stream Path> messages.
The <Inactive Source> message was new in Version 1.3a.
CEC 13.3
System Standby
CEC 13.3.1
Messages
The following message is used for the System Standby feature:
<Standby>
For details of which messages are mandatory, see CEC Table 10, CEC Table 27 and CEC Table 28.
CEC 13.3.2
Feature Description
The broadcast message <Standby> can be used to switch all CEC devices to the Standby state. A typical
scenario where the user sets the whole system to the Standby state is shown below:
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TV
Version 1.4b
Device 1 Device 2 Device 3
All devices go
to Standby
user selects System Standby
<Standby> (broadcast address)
CEC Figure 13 A typical scenario for the broadcast (system) Standby feature
The whole system may be set to the Standby state by broadcasting the <Standby> message. It is
manufacturer dependent on how to differentiate between a <Standby> message for a single device, e.g. a
STB, and System Standby message (broadcast to the whole system). For example, the system or broadcast
<Standby> message may be sent as the result of a long press on the local or remote control Standby button.
A device can switch another single device into the Standby state by sending the message <Standby> as a
directly addressed message to it.
TV
Device
Single device
goes to
Standby
user selects specific Standby
<Standby> (specific device address)
CEC Figure 14 A typical scenario for the Standby feature to a specific device
When a source device is put to Standby by the user (e.g. by its own remote control or local key), it shall not
broadcast a system <Standby> message unless explicitly requested by the user.
A <Standby> message is not a toggle and can only send a device to the Standby state: other messages shall
be used to activate a device, i.e. bring a device out of the Standby state.
A <Standby> message should not interrupt any background tasks such as a recording - see Timed Recording,
section CEC 13.5.3.
Devices can ignore <Standby> messages if they are in a state where going into the Standby state is not the
appropriate action or due to device limitations it is not possible to go to the Standby state. For example:
The device is recording;
The device only has a mechanical power switch;
It only provides limited facilities for external control of its power;
The Standby function is disabled;
It is a device, such as a PC, which is performing other functions that should be left running;
High priority services, such as the reception of emergency announcements or similar, shall continue.
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CEC 13.3.3
Version 1.4b
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
When sending this Message
From Version 1.3a or
later Device
To Version 1.3 or
earlier Device
Possible behavior
<Standby>
Any
Source or recorder
When a <Standby> message is sent
during a recording:
- the target might not ignore the
<Standby> message;
- the target might not go to the
Standby state after a recording.
(These were manufacturer decisions
clarified in 1.3a.)
CEC 13.4
One Touch Record
CEC 13.4.1
Messages
The following messages are used for the One Touch Record feature:
<Record Off>, <Record On>, <Record Status>, <Record TV Screen>
For details of which messages are mandatory, see CEC Table 11, CEC Table 27 and CEC Table 28.
CEC 13.4.2
Feature Description
This feature allows the user to easily start a recording of the source that is being displayed on the TV, just by
selecting a Recording Device and giving the record command. It is not always possible to carry out a One
Touch Record as it depends on what source is currently being displayed. It is primarily used for the instant
recording of a tuner service, or the recording of another device (e.g. Camcorder) connected externally to the
Recording Device
Either the TV or the Recording Device may initiate the One Touch Record Feature, for example by selecting
a menu option on the TV or by pressing record on the Recording Device.
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Recording
Device
Version 1.4b
TV
User presses
One Touch Record
<Record TV Screen>
TV is displaying
a tuner Service
<Record On> ["Digital Service Identification"]
<Record On> [“Analogue Service]
<Record Status> ["Recording Digital Service"]
<Record Status> ["Recording Analogue Service"]
CEC Figure 15 A typical scenario for the One Touch Record feature
In the event of the Recording Device initiating the feature, it should send a <Record TV Screen> message to
the TV. On receipt of the <Record TV Screen> message by the TV, or if the user initiates the One Touch
Record feature via the TV, the TV shall react as follows:
If the TV is currently displaying an internal tuner service, it shall respond with a <Record On> [“Digital
Service”] [Digital Service Identification] message or a <Record On> [“Analogue Service”] [Analogue
Broadcast Type] [Analogue Frequency] [Broadcast System] message.
If the Recording Device is the current active source device, then the TV shall respond with a
<Record On> [“Own source”] message.
If the TV is currently displaying an external input and it knows the Physical Address of the external
source (e.g. it has a map of which external devices are connected), then the TV may send a <Record
On>[External Physical Address] message. The TV may alternatively send a <Record On>[External Plug
Number] message if it knows the relevant plug number on the recorder for the external source.
If the TV is currently displaying some other source, it shall respond with a <Feature Abort> [“Cannot
provide source”] message, or do nothing if initiated via the TV.
On receipt of a <Record On> message the Recording Device shall act as follows:
If [“Digital Service”] or [“Analogue Service”] is indicated and the device can record that service using the
information that was sent, the device shall change to that service and start recording. If the device does
not have the indicated type of tuner, then it should respond with a <Record Status> with an operand of
[“No recording – unable to record Digital Service”] or [“No recording – unable to record Analogue
Service”].
If the recorder has a suitable tuner, but is not able to select a service because the requested parameters
are invalid or out of the range of the tuner, then it should return “No recording – Unable to select required
service”.
If [“Own source”] is indicated, then it shall attempt to record whatever it is currently displaying, e.g. an
external connection such as a camcorder or the service it is currently tuned to.
If [“External Plug”] or [“External Physical Address”] is indicated, the recorder should switch to the
connector indicated by the External Plug number, or the connector which has the input from the device
identified by the external Physical Address, and return a status of “Recording External input”. If [External
Plug] or the [External Physical Address] is invalid, the device should return “No recording – invalid
External plug number” or “No recording – invalid External Physical Address” respectively.
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The Recording Device shall respond with the message <Record Status> to indicate if recording has begun, or
a reason why recording has failed. If the recording failed to start, the TV should inform the user, with the
reason, or take other appropriate action. Note that it may take several seconds or more before a recorder is
able to send an accurate <Record Status> after receiving a <Record On> message.
A recording initiated by a <Record On> message may be stopped at any time by sending a <Record Off>
message. The Recording Device should then stop recording immediately. The recorder may optionally send a
<Record Status> message in response to a <Record Off> message. In this case, the recorder may indicate
that the recording was terminated normally by the <Record Off> message, or that the recording had already
terminated, e.g. because there was insufficient space available on the media.
When a recorder is making a recording, the system <Standby> message should not interrupt a recording in
progress. If the recorder receives a <Standby> message during the recording, it should react to the
<Standby> message when the recording has finished unless it is the Active Source at the end of the
recording.
The TV should ignore a <Record TV Screen> message that comes from a non-Recording Device address,
however it shall accept the message from a ‘Reserved’ Logical Address (a future device type).
CEC 13.4.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
When sending this Message
From Version 1.3a or
later Device
To Version 1.3 or
earlier Device
Possible behavior
<Record On>
TV
Recording Device
<Feature Abort>, when specifying a
[Record Source] other than “Own
Source”
<Record Status > after a
<Record Off> message
Recording Device
TV
<Feature Abort> as sending a
<Record Status> in this case was new
in 1.3a
When sending this Message
From Version 1.3 or
earlier Device
To Version 1.3a or
later Device
Possible behavior
<Record On>
TV
Recording Device
<Feature Abort> as <Record On> is
optional in 1.3a or later
CEC 13.5
Timer Programming
CEC 13.5.1
Messages
The following messages are used for the Timer Programming feature:
<Clear Analogue Timer>, <Clear Digital Timer>, <Clear External Timer>, <Set Analogue Timer>,
<Set Digital Timer>, <Set External Timer>, <Set Timer Program Title>, <Timer Cleared Status>, <Timer
Status>
For details of which messages are mandatory, see CEC Table 12, CEC Table 27 and CEC Table 28.
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CEC 13.5.2
Version 1.4b
Feature Description
This feature allows a device (e.g. the TV) to set a timer recording on a Recording Device. It may for example
be used to set timer blocks of a Recording Device via a TV menu or via an EPG.
A device, such as the TV, may set or clear an individual timer block of a Recording Device. The Recording
Device will respond to indicate if the timer was successfully set/cleared.
A timer block is set in the Recording Device by sending it a <Set Analogue Timer>, <Set Digital Timer> or a
<Set External Timer> message, according to the type of service to be recorded.
TV
Recording Device
selects programme to record via TV EPG
<Set Analogue Timer> or
<Set Digital Timer>
<Timer Status>
optional
<Set Timer Programme Title>
...
selects to clear previous recording via TV EPG
<Clear Analogue Timer> or
<Clear Digital Timer>
<Timer Cleared Status>
CEC Figure 16 A typical scenario for setting a Timer Record Block
The Recording Device shall respond to the TV to indicate that a Timer was successfully programmed with a
<Timer Status> message. For instance, there may be a conflict with an existing Timer, or the tuner in the
Recording Device might not be of the correct Type (e.g. transmission system and/or CA). Note that it may
take several seconds or more before a recorder is able to send an accurate <Timer Status> or <Timer
Cleared Status> after receiving the relevant Set Timer or Clear Timer message.
The Recording Device may optionally include an estimate of the duration available on the media when:
There is not, or might not be, sufficient space available for recording; or
The timer was not successfully programmed because the event already exists.
Note that duration estimate might not be accurate with variable bitrate recordings, such as with a broadcast
TV stream.
It is also possible to transfer the program title of a timer block (where for instance a timer is set via an EPG).
To achieve this a device may send a <Set Timer Program Title> message directly after sending <Set
Analogue Timer>, <Set Digital Timer> or <Set External Timer>. The Recording Device may then store the
program title along with the timer information. If the Recording Device does not support program titles, then it
shall respond with a <Feature Abort> message to an incoming <Set Timer Program Title> message.
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When a recorder is making a recording, the system <Standby> message should not interrupt a recording in
progress. If the recorder receives a <Standby> message during the recording, it should react to the
<Standby> message when the recording has finished unless it is the Active Source at the end of the
recording.
CEC 13.5.3
Performing a Timed Recording using another device as source
When recording using another source device, e.g. recording a separate STB, the signal connection to the
recorder will be made using another link such as an analogue connection or a SCART lead.
The <Set External Timer> message can be used to set a Timer in a Recording Device so that it uses an
external (non-HDMI) connection as the source. There are two methods of specifying which connector the
recorder should use: External Plug and External Physical Address, as specified in [External Source
Specifier]:
When “External Plug” has been specified, the recorder switches to the indicated plug number. Note that,
in this case, the user (or an application in the TV) will have to supply the relevant External Plug number.
When “External Physical Address” has been specified, the recorder switches to the relevant connector
for the external device identified by the External Physical Address. Note that, in this case, the mapping
of External Physical Address to recorder input connector is stored in the Recording Device. This
mapping is usually made at installation time.
When the Recording Device starts a timed recording, it shall send a <Record On> message to the external
tuner (STB) with the relevant operand to select the required service (analogue, digital or own source).
Operation of this message is as described in the One Touch Record feature (see section CEC 13.4) and will
cause the external device to come out of the Standby state if necessary. In this case, it shall do so “silently”
without sending any <Image View On> or <Active Source> messages and shall provide an output on the
separate link (e.g. SCART).
If the recorder initiated a recording using a <Record On> message to an external source, it shall also send a
<Record Off> message to that source when the recording has finished, or when the recorder was unable to
complete a recording for any reason (e.g. it has run out of media).
If the Source Device receives a <Standby> message during the recording, it shall ignore it for the duration of
the recording and go to the Standby state after it has completed the recording (i.e. after receiving the
<Record Off> message), unless it is the Active Source at the end of the recording.
CEC 13.5.4
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
This feature was introduced in Version 1.3a. Devices conforming to Version 1.3 or earlier will respond with a
<Feature Abort> message to all messages sent by an Initiator for this feature.
CEC 13.6
System Information
CEC 13.6.1
Messages
The following messages are used for the System Information feature:
<CEC Version>, <Get CEC Version>, <Get Menu Language>, <Give Physical Address>, <Polling Message>,
<Report Physical Address>, <Set Menu Language>.
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For details of which messages are mandatory, see CEC Table 13, CEC Table 27 and CEC Table 28.
CEC 13.6.2
Feature Description
This feature allows devices to automatically use the same OSD and Menu language settings as the TV.
When a source device is powered on, it should send a <Get Menu Language> message to the TV. The TV
shall then respond as shown below with a <Set Menu Language> message.
Device
TV
<Get Menu Language>
<Set Menu Language>
CEC Figure 17 Message exchange when getting the TV’s menu Language
When the user changes a menu language setting on the TV, it shall send a <Set Menu Language> message
containing the currently selected menu [Language], as shown below.
TV
Device
Device uses
new Language
user selects new menu language
<Set Menu Language> [Language]
CEC Figure 18 A typical scenario when a menu language setting within the TV is modified
On receipt of the <Set Menu Language> message, the device shall attempt to use the newly selected
[Language] for Menus and OSDs. This message may be ignored by:
devices where the user has specifically disabled this function; or
Mobile Devices; or
devices which are not able to change the language by CEC messages, e.g. a PC; or
devices without OSD/ Menu generation capabilities.
If the device does not support the requested language, it shall ignore this <Set Menu Language> message.
Note that a device might receive a <Set Menu Language> message even when the language has not been
changed. A device shall ignore any of the above messages that come from an Initiator address other than 0
(the TV).
Devices which have Logical Addresses other than 0 (TV) or 14 (when a TV) shall send a <Feature
Abort>[“Unrecognized opcode”] message in response to a <Get Menu Language> message and shall not
send <Set Menu Language> messages.
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When identifying a language, the Bibliographic codes of ISO/FDIS 639-2 [ref 1n] shall be used. In accordance
with this standard, only codes using strings of lower-case characters shall be used by a TV. For robustness
reasons, non-TV devices should accept any mixture of upper- and lower-case characters.
Note that in the case of Chinese, both the Terminology code "zho" and the Bibliographic code "chi" are used.
Where a device supports both Simple and Traditional characters, "zho" should be used for Simple characters
and "chi" for Traditional characters. Where a device only supports one set (either Simple or Traditional), then
the other code should default to the same character set. For example, if a device only supports Simple
characters ("zho") it should also use these when the language is set to "chi" (Traditional).
A device may ask another device to indicate which Version of CEC the target device supports. It shall do this
by sending a <Get CEC Version> message. The target device should respond with a <CEC Version>
message, which includes the relevant [CEC Version] operand.
CEC 13.6.3
Additional Information
The <Polling Message> is used to detect the presence or absence of a device within the system, see 6.1.3. It
is also used for allocating Logical Addresses as detailed in CEC 10.2.1.
The <Report Physical Address> message is used by a device to broadcast its Physical Address to all other
devices in the system. By using the logical and Physical Addresses, any other device is able to derive the
physical connectivity of the network. A device may request the Physical Address of another device by
sending a directly addressed <Give Physical Address> message to it.
CEC 13.6.4
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.4.
<CEC Version> for devices conforming to Version 1.4 and later does not give any information about the
HDMI Version used.
<Set Menu Language>: Non-TV devices conforming to Versions 1.3a and earlier may broadcast this
message and might not accept a mixture of upper- and lower-case characters for [Language].
<Get Menu Language>: A TV conforming to Versions 1.3a and earlier may send this message.
<Get CEC Version> and <CEC Version> were new messages for Version 1.3a.
CEC 13.7
Deck Control
CEC 13.7.1
Messages
The following messages are used for the Deck Control feature:
<Deck Status>, <Give Deck Status>, <Deck Control>, <Play>
For details of which messages are mandatory, see CEC Table 14, CEC Table 27 and CEC Table 28.
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CEC 13.7.2
Version 1.4b
Feature Description
This feature allows a Playback Device (a deck or disc player or recorder) to be controlled by another device
(e.g. the TV). Messages are also provided to allow a device to find out the status of the Deck; this allows, for
example, a TV to keep its user interface synchronized with the status of the Deck.
A device may query the status of a deck with the <Give Deck Status> command. The deck should respond
with a <Deck Status> message.
A device may control a Deck with the <Play> and <Deck Control> messages. These messages may be
initiated after a user command. The Deck shall act upon the command that it receives within the messages
<Play> and <Deck Control>. It is the equivalent of the user selecting the command local to the Deck. If the
deck cannot carry out the command (e.g. it has no media when trying to play) it should respond with a
<Feature Abort> [“Not in correct mode to respond”] message.
If the deck is in the Standby state and receives a <Deck Control> [“Eject”] or <Play> [“Play Forward”]
message, it should power on and act on the message. It is up to the manufacturer to decide if the device
should power on when receiving any other <Deck Control> or <Play> messages.
TV
Playback Device ('Deck')
<Give Deck Status> ["On"]
<Deck Status> ["Stop"]
Selects 'Play' via TV UI
<Play> ["Forward"]
<Deck Status> ["Play"]
Selects 'Next Chapter' via TV UI
<Deck Control> ["Skip Forward"]
<Deck Status> ["Skip Forward"]
CEC Figure 19 A typical scenario for the Deck Control feature
The effect of the <Play> [Play Mode] operands "Fast Forward xx" and "Fast Reverse xx" will depend on the
target device. For a disc-based sytem (e.g. DVD, Hard Disk), these will usually produce a picture at the
required speed and direction. However, for a tape deck, the previous deck state may affect how this message
is executed so that a picture might not always be available.
The effect of the <Deck Control> [Deck Control Mode] operands "Skip xx" will also depend on the target
device. For a disc-based system, this will cause the disc to skip to the next Chapter. For a tape, this will
cause the tape to go to the next marker without displaying a picture.
CEC 13.7.3
Behavior with Earlier Versions
There are no differences for this Feature between a Version 1.4b device and a device implementing earlier
versions of CEC.
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CEC 13.8
Tuner Control
CEC 13.8.1
Messages
Version 1.4b
The following message are used for the Tuner Control feature:
<Give Tuner Device Status>, <Record On>, <Select Analogue Service>, <Select Digital Service>. <Tuner
Step Decrement>, <Tuner Step Increment>, <Tuner Device Status>
For details of which messages are mandatory, see CEC Table 15, CEC Table 27 and CEC Table 28.
CEC 13.8.2
Feature Description
This feature allows a device (e.g. the TV) to control another CEC device’s tuner.
TV
Device
user selects next higher (or lower)
service from the programme list
<Tuner Step Increment (or decrement)>
CEC Figure 20 A typical scenario for selecting a new Service
A device can control a CEC Device’s tuner using the <Tuner Step Increment> and <Tuner Step Decrement>
messages. If a device receives the <Tuner Step Increment> or <Tuner Step Decrement> message then it
should select the next highest or next lowest service in its service list. The tuner device can interpret the
messages as it chooses, for example, it may only cycle through channels included in the user’s list of
favorites.
A device can select a digital service on a tuner device by sending the <Select Digital Service> message. The
tuner device shall then attempt to tune to that digital service and stream its output on the HDMI connection. If
the specified digital service is not supported on the device then it should send a <Feature Abort> [“Invalid
operand”] message. If the tuner device cannot select that digital service (e.g. if it is recording), it should
respond with a <Feature Abort> [“Refused”] message. In a similar way, an analogue service may also be
selected using the <Select Analogue Service> message.
A device may query the status of a tuner device by sending a <Give Tuner Device Status> message. The
tuner device shall respond by sending a <Tuner Device Status> message indicating if it is currently displaying
its tuner and the service that is currently selected.
A <Record On> message may be sent to a tuner when making an external recording. For details, see CEC
13.5.3.
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CEC 13.8.3
Version 1.4b
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
<Select Analogue Service> was a new message for Version 1.3a.
CEC 13.9
Vendor Specific Commands
CEC 13.9.1
Messages
The following messages are used for the Vendor Specific Commands feature:
<Device Vendor ID>, <Give Device Vendor ID>, <Vendor Command>, <Vendor Command With ID>,
<Vendor Remote Button Down>, <Vendor Remote Button Up>
For details of which messages are mandatory, see CEC Table 16, CEC Table 27 and CEC Table 28.
CEC 13.9.2
Feature Description
This feature allows a set of vendor specific commands to be used to communicate between devices.
A device that supports vendor specific commands shall store a Vendor ID. A device shall broadcast a
<Device Vendor ID> message after a successful initialization and address allocation to inform all other
devices of its vendor ID. A device may request the Vendor ID of another device by sending a <Give Device
Vendor ID> message to it. The Follower shall respond by broadcasting a <Device Vendor ID> message. In
this way any device can determine the vendor of another device.
A device shall attempt to transmit a directly addressed <Vendor Command> to another device only if it has
obtained or received the Vendor ID of that device and it recognizes that Vendor ID. A device should only
send a <Vendor Command> if it has previously sent a <Device Vendor ID> message.
A Follower device may accept a <Vendor Command> from an Initiator of the same Vendor ID. With the
agreement of the vendors involved, it is also possible for a device to accept a <Vendor Command> from
devices made by other vendors. The Follower may accept a <Vendor Command> only if the Initiator’s Vendor
ID matches a Vendor ID on the Follower’s internal list of acceptable Vendor IDs. It should ignore all
messages coming from devices with Vendor IDs which it does not recognize. This behavior was not allowed
in Versions before 1.3a and so a device that wishes to send <Vendor Command> messages between
different vendors in this way shall first discover whether the target conforms to Version 1.3a or later, by
sending a <Get CEC Version> message. A Follower conforming to Version 1.3a or later and supporting such
<Vendor Command> messages between different vendors shall respond with a <CEC Version> message. If
the Follower responds with a CEC Version of 1.3a or later, then the Initiator device can continue by sending
the required <Vendor Command>. Note that sending a <Get CEC Version> message does not need to be
done every time a device wishes to send a <Vendor Command> to another device from a different vendor - if
the Initiator already knows the CEC Version of the target then it is not necessary to send a <Get CEC
Version> message.
If an Initiator device wants to send a <Vendor Command> and it does not know the Vendor ID of the Follower
device, the Initiator device shall send a <Give Device Vendor ID> message to the Follower device before it
sends the <Vendor Command>. The Follower device may respond to the received <Vendor Command>. It
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should only respond without previously sending a <Give Device Vendor ID> message if the Follower device
already knows the Vendor ID of the initiating device.
The <Vendor Command With ID> message may be broadcast as well as directly addressed. This differs from
the <Vendor Command> in that the first 3 bytes of the payload carry a Vendor ID which identifies the vendor
or entity which defined the command. Devices which receive the <Vendor Command With ID> and which do
not accept the Vendor ID contained in the command shall ignore this command and shall respond with a
<Feature Abort> if the message was directly addressed to that receiving device.
It is possible to send vendor specific remote control commands using the <Vendor Remote Button Down>
and <Vendor Remote Button Up> messages. These messages use the mechanism and timing, as described
in section CEC 13.13.2 Remote Control Pass Through, for <User Control Pressed> and <User Control
Released> messages.
TV
Device
presses RC button
<Vendor Remote Button Down>
releases RC button
<Vendor Remote Button Up>
CEC Figure 21 The messages sent in the Vendor Specific Commands feature
In addition it is possible to send other (non remote control key) vendor specific messages using the <Vendor
Command> and <Vendor Command With ID> messages. The message parameter(s) can be used to
communicate any additional (vendor defined) messages and data.
CEC 13.9.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
<Vendor Command With ID> was a new message for Version 1.3a.
In Version 1.3a or later, by agreement of the vendors involved, <Vendor Command> messages may be used
by devices which do not have the same Vendor ID.
CEC 13.10
OSD Display
CEC 13.10.1
Messages
The following message is used for the OSD Display feature:
<Set OSD String>
For details of which messages are mandatory, see CEC Table 17, CEC Table 27 and CEC Table 28.
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CEC 13.10.2
Version 1.4b
Feature Description
This feature allows a device to transfer a text string to the TV for On Screen Display. The <Set OSD String>
message is used to transfer the text string to the TV. The time that the OSD string is displayed on the TV is
specified by the [Display Control] parameter:
“Display for default time”: the display is shown for a default period defined by the TV, e.g. 5 seconds,
and then removed automatically;
“Display until cleared”: the string is displayed on the screen until it is explicitly cleared or its power is
removed. When an Initiator uses this value it shall send a <Set OSD String> message containing a
[Display Control] parameter of “Clear previous message” in order to clear the message after the user has
had time to read the message;
“Clear previous message” clears any displayed string. Note that when [Display Control] has this value,
the [OSD String] parameter shall not be used.
The TV shall display the whole string unless it is in an unsuitable state or it cannot display the complete
message, in which case it shall generate a <Feature Abort> message with relevant [Abort Reason], e.g. “not
in correct mode to respond” or “invalid operand”.
If a new <Set OSD String> message with a [Display Control] of “Display for default time” or “Display until
cleared” is received when an OSD String is already being displayed, it should overwrite the existing string.
OSD Strings generated locally within the TV may also overwrite any messages sent via the <Set OSD
String> message.
CEC 13.10.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.4.
TV’s conforming to Version 1.3a or earlier might not respond with a <Feature Abort> message when they are
not able to display the complete string.
There are no differences for this Feature between a Version 1.3a device and a device implementing earlier
versions of CEC
CEC 13.11
Device OSD Name Transfer
CEC 13.11.1
Messages
The following messages are used for the Device OSD Name Transfer feature:
<Give OSD Name>, <Set OSD Name>
For details of which messages are mandatory, see CEC Table 18, CEC Table 27 and CEC Table 28.
CEC 13.11.2
Feature Description
This feature is used to request the preferred name of a device to be used in any on-screen display (e.g.
menus), which reference that device. A device (e.g. the TV) may request another device’s name by sending a
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directly addressed <Give OSD Name> message to it. If the device supports this feature it shall respond with a
<Set OSD Name> message. The device’s name should then be used in on-screen references to it.
A device that implements more than one type of CEC functionality, e.g. a recorder with an internal tuner, and
has more than one Logical Address (see CEC 10.2) should respond with the same [OSD Name] for each
Logical Address. It is recommended that the [OSD Name] refers to the complete physical product, rather than
the individual CEC functionality, in order to avoid user confusion. It is manufacturer-dependent how the
individual CEC functionalities (e.g. the tuner or recorder in the above example) are presented to the user.
A TV may send a <Give OSD Name> message whenever it discovers a new device that has been connected.
CEC 13.11.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.4.
Devices conforming to Version 1.3a or earlier with several Logical Addresses might respond with a different
[OSD Name] for each implemented Logical Address.
A TV conforming to Version 1.3a or later might not send a <Give OSD Name> message when it discovers a
new device.
CEC 13.12
Device Menu Control
CEC 13.12.1
Messages
The following messages are used for the Device Menu Control feature:
<User Control Pressed>, <User Control Released>, <Menu Request>, <Menu Status>
For details of which messages are mandatory, see CEC Table 19, CEC Table 27 and CEC Table 28.
CEC 13.12.2
Feature Description
This feature allows device menus to be controlled via the TV remote control as if it was using its own remote
control and allow the TV to be aware when another device has a menu on its display.
A device shall indicate that it is displaying a menu by sending a <Menu Status> [“Activated”] message to the
TV. If the device leaves the menu it shall send a <Menu Status> [“Deactivated”] message to the TV. The TV
should then handle incoming remote control commands internally (as it would normally).
The message <User Control Pressed> can be used to send incoming Remote Control commands from the
TV to a device that it is displaying a menu. The <User Control Released> message should be sent on release
of the RC button. If a device fails to acknowledge any <User Control Pressed> or <User Control Released>
message when in the providing menu state, the TV can assume that it has been removed from the system
and act accordingly. For more information on the User Control messages and timing see the Remote Control
Pass Through feature description (CEC 13.13).
The TV may initiate a device’s menu by sending a <Menu Request> [“Activate”] command. It may
subsequently remove the menu by sending a <Menu Request> [“Deactivate”] message. The TV may also
query a devices menu status by sending a <Menu Request> [“Query”]. The menu device shall always
respond with a <Menu Status> command when it receives a <Menu Request>.
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A new active source device shall send a <Menu Status> [“Activated”] message to the TV if it is displaying a
menu. The TV shall assume that a new active source is not in a menu unless it receives this message after
the <Active Source> message. The TV shall ignore a <Menu Status> message coming from a device that is
not the current active source. A source device shall only send <Menu Status> commands when it is the
current active source.
CEC 13.12.3
Behavior with Earlier Versions
There are no differences for this Feature between a Version 1.4b device and a device implementing earlier
versions of CEC.
CEC 13.13
Remote Control Pass Through
CEC 13.13.1
Messages
The following messages are used for the Remote Control Pass Through feature:
<User Control Pressed>, <User Control Released>
For details of which messages are mandatory, see CEC Table 20, CEC Table 27 and CEC Table 28.
CEC 13.13.2
Feature Description
This feature is used to pass remote control commands received by one device (typically the TV) through to
another device in the network. This feature will typically be used in situations where a TV offers a remote
control with additional modes for controlling other devices within the system. The TV will receive the RC
command and typically pass the command through to the appropriate device, see section CEC 13.13.4.
The Initiator will send a <User Control Pressed> message when the remote control button is pressed. When
the button is released, devices that do not implement Press and Hold operation (see CEC 13.13.3) should
send a <User Control Released> message immediately. For devices that do implement Press and Hold
operation, see section CEC 13.13.3.
Target
TV
User presses the TV’s
remote control key (or
local key)
User quickly releases
key
<User Control Pressed> [UI Command]
Target interprets key in
same way as a local
keypress
<User Control Released>
CEC Figure 22 A typical scenario where the user presses and quickly releases a key
The Initiator may send further <User Control Pressed> messages without interleaving <User Control
Released> messages if a new button press occurs quickly after a button release, for example within the
Initiator Repetition Time defined in CEC 13.13.3(1). This has the same effect as sending a <User Control
Released> for the first button.
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The <User Control Pressed> and <User Control Released> messages indicate that the user has pressed and
released the relevant button on their remote control. For the non-Deterministic commands (i.e. those
commands in CEC Table 30 which are not mentioned in Table 6), the response may be device-dependent
and it is recommended that the Follower interprets those <User Control Pressed> and <User Control
Released> messages in the same way as when a user presses and releases the corresponding buttons on
device’s own remote controller.
If a Follower does not receive a <User Control Released> message (or another <User Control Pressed>
message) within an appropriate time period equal to the Follower Safety Timeout period, it shall assume that
the button has been released and act accordingly. For details of the Follower Safety Timeout period see CEC
13.13.3 (2), which defines Press and Hold Operation,
A device that has initiated a <User Control Pressed> message shall ensure that it sends a <User Control
Released> message before going into the Standby state, if the <User Control Pressed> message requires an
associated <User Control Released> message. In the event that the Initiator of the message is powered off or
its HDMI cable is disconnected before sending a <User Control Released> message, the Follower will never
receive the <User Control Released> message.
CEC 13.13.3
Press and Hold Operation
Press and Hold Operation is used in order to indicate to another device that the user presses and keeps
pressing the same remote control button for a long time. A device supporting Press and Hold Operation as
either an Initiator or a Follower shall follow the rules described in this subsection.
(1) Initiator Behavior
When the user presses and keeps pressing the same remote control button for a long time, the Initiator shall
send repeated <User Control Pressed> messages containing the same [UI Command]. In this case, the
Initiator does not interleave <User Control Released> messages, but it shall send a <User Control Released>
message immediately when the user releases the key.
Initiator
Repetition time
If the user presses and keeps pressing a key for a long time and then releases the first key and presses
another key within the Initiator Repetition Time (see below), then it is not necessary to send a <User Control
Released> message when the first key is released because the <User Control Pressed> with the second [UI
Command] acts as the <User Control Released> message for the first key. If the second key is pressed after
the Initiator Repetition Time, the Initiator shall send a <User Control Released> message.
CEC Figure 23 A typical scenario where the user presses and holds a key
When the Initiator sends such repeated <User Control Pressed> messages, it shall send them using an
Initiator Repetition Time with a minimum of 200ms and a maximum of 500ms. The recommended Initiator
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Repetition Time is 450ms– see CEC Figure 24 below. Implementers should note that using timings near the
maximum value may result in incorrect press and hold behavior (as this is very close to the Follower Safety
Timeout period of the Follower) and that using timings near the minimum value places an unnecessarily
heavy load on the CEC line.
The time between messages for the Initiator Repetition Time is measured from the same point on each
message, e.g. between the first falling edge of the Start Bit in each message.
Note that many remote controls send their remote control commands, e.g. using infra-red, at high speeds
which are too fast to be carried directly on the CEC line. It is important that the <User Control Pressed>
messages shall not be sent using the minimum Initiator Repetition Time specified above.
Initiator receives infra-red
command, sends CEC message
and starts Initiator Repetition timer
Min
Recommended
Initiator detects that user has
stopped pressing Remote Control
button and immediately sends a
<User Control Released> message
Max
Initiator re-starts
Initiator Repetition
Time timer
0
Time, ms
UC P
0
450 500
200
UC P
Time, ms
Recommended min
Follower Safety Timeout
UC P = <User Control Pressed>
UC R
UC R = <User Control Released>
500 550
Min Follower
Safety Timeout
Follower receives message
and starts Follower Safety
Timeout timer
Press and Hold behavior
Single action, eg
single Volume
increment
At second <User Control Pressed> with the same
[UI Command] within the Follower Safety Timeout
period, the Follower may start its Press and Hold
behavior, eg accelerated Volume steps.
Follower re-starts Follower Safety Timeout timer.
At <User Control Released>,
Follower stops receiver actions
and cancels Press and Hold
behavior
CEC Figure 24 Initiator Repetition Time, Follower Safety Timeout and Press and Hold behavior
(2) Follower Behavior
The Follower Safety Timeout period of a Follower supporting Press and Hold operation should not be less
than 500ms and is recommended to be at least 550ms. The time between messages for the Follower Safety
Timeout period is measured from the end of the message, i.e. when the Follower receives a Data Block
where the EOM bit is set to ‘1’.
The Follower shall start the Press and Hold behavior (see CEC Figure 24 above) when another <User
Control Pressed> message containing the same [UI Command] is received within the Follower Safety
Timeout period.
The press and hold behavior (e.g. increment step, speed, etc) is defined by the Follower and should
have the same behavior when using CEC as when one of the local keys are pressed or when using its
own remote control;
It is optional for the Follower to start Press and Hold behavior after the first <User Control Pressed>
message has been received. Note that if the Press and Hold behavior starts at the first <User Control
Pressed> message, then the Follower may make several increments before the user can release the
key.
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The Follower shall stop its Press and Hold behavior for the previous [UI Command] when:
A <User Control Pressed> message containing a different (new) [UI Command] is received within the
Follower Safety Timeout period; or
The Follower Safety Timeout period has expired.
In the above two cases, the Follower should assume that it has received a <User Control Released>
message.
The Follower shall stop its Press and Hold behavior for the previous [UI Command] before it handles the
<User Control Pressed> message for a new [UI command].
It is the Follower’s decision as to whether the forwarded [UI Command] is executed as a single-shot event or
part of a Press and Hold sequence.
CEC 13.13.4
RC Key Forwarding Recommendations
In order to allow for “single remote control” system operation, whereby, for example, the TV’s remote
controller is used to control other devices by sending User Control messages, the TV should send to the
appropriate device as many key presses as possible which the TV does not require itself or does not require
in its current state, using <User Control Pressed> and associated <User Control Released> messages.
CEC 13.13.5
Other uses of <User Control Pressed>
The <User Control Pressed> message may also be sent in other cases which are not the direct result of a
user interaction, nor directly mapped to a Remote Control key. For example, a TV might offer the user a way
to access the root menu of connected devices from a menu in the TV UI. If the user selects that item in the
TV UI, the TV will send a <User Control Pressed> [“Root Menu”] to the corresponding device. The Initiator
(the TV in this example) should also send the corresponding <User Control Released> message.
If a Follower is not in a state where it can action those messages, e.g. it is in Standby, then it may send a
<Feature Abort> message with an [Abort Reason] of “Not in correct mode to respond” (preferred) or “Unable
to determine”.
In order to deterministically change the power status of the target device, it is recommended to use the
relevant deterministic functions 0x6D, 0x6C or 0x6B instead of ["Power"], 0x40, because 0x40 might not have
predictable behavior. If it is necessary to deterministically change the power status of the target device by
using 0x40, then the Initiator should first enquire the Power Status of the target device by sending a <Give
Device Power Status> message. In this case, if the target device is already in the desired power state, then
the Initiator shall not send a <User Control Pressed> ["Power"] message.
CEC 13.13.6
Deterministic UI Functions
In CEC Table 30, codes 0x60 to 0x6D are identified as Functions. Unlike the other codes, which just pass
remote control presses to the target (often with device-specific results), the Functions are deterministic, i.e.
they specify exactly the state after executing these commands. Several of these also have further operands,
specifying the function in more detail, immediately following the relevant [UI Command] operand. For further
information on the additional operands below, refer to Table 29.
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CEC Table 6 Deterministic UI Functions
UI Command
Code
User Operation
Function
Additional Operands
0x60
Play Function
Specifies Play mode
0x61
Pause-Play Function
Pauses playback. If
repeated, the device shall
remain in the paused state.
2
Start recording. If repeated,
the device shall remain in
the record state without
interrupting the recording.
2
Pauses the recording. If
repeated, the device shall
remain paused.
2
Stops the media. If
repeated, the device shall
remain stopped.
2
0x62
0x63
0x64
Record Function
Pause-Record Function
Stop Function
[Play Mode]
Notes
1, 2
0x65
Mute Function
Mutes audio output. If
repeated, the audio shall
stay muted.
0x66
Restore Volume
Restores audio output to
the value before it was
muted.
0x67
Tune Function
Identifies a broadcast
channel number
[Channel Identifier]
0x68
Select Media Function
Selects one Media within a
device
[UI Function Media]
0x69
Select A/V Input Function
Selects an A/V input
[UI Function Select A/V input]
1, 2
0x6A
Select Audio Input Function
Selects an Audio input
[UI Function Select Audio input]
1, 2
0x6B
Power Toggle Function
Toggles the device’s power
state (On / Standby)
2
0x6C
Power Off Function
Puts the device into the
Standby state. If repeated,
the device stays in the
Standby state.
2
0x6D
Power On Function
1, 2
1, 2
Puts the device into the On
(non-Standby) state. If
repeated, the device stays
in the active state
Notes:
1
Functions with additional operands may also be used without the additional operand: in this case the
behavior is device-specific.
2
During a recording or timed recording, a device may ask the user for confirmation of this action
before executing it.
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CEC 13.13.7
Version 1.4b
Non-Deterministic Commands with Parameters
Some non-deterministic commands have parameters. Unlike the deterministic Functions, the exact behavior
of these commands is not fully specified. The following non-deterministic commands with parameters are
defined:
CEC Table 7 Non-deterministic UI commands with parameters
UI Command
Code
User Operation
Additional Operands
0x56
Select Broadcast Type
[UI Broadcast Type]
0x57
Select Sound
Presentation
[UI Sound Presentation
Control]
CEC 13.13.8
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.4.
Version 1.4 added [“Media Top Menu”], [“Media Context-sensitive Menu”], [“Number Entry Mode”], [“Number
11”], [“Number 12”], [“Select Broadcast Type”] and [“Select Sound Presentation”] UI commands. It also
clarified the earlier [“Number 0”] to be [“Number 0 or Number 10”] (0x20).
Version 1.3a added [“Record Stop”], [“Record Pause”], [“Power Off Function”], [“Power On Function”] and
[“Data”] UI commands. It also clarified the earlier [“Power Function”] to be [“Power Toggle Function”] (0x6B).
CEC 13.14
Give Device Power Status
CEC 13.14.1
Messages
The following messages are used for the Give Device Power Status feature:
<Give Device Power Status>, <Report Power Status>
For details of which messages are mandatory, see CEC Table 21, CEC Table 27 and CEC Table 28.
CEC 13.14.2
Feature Description
Several messages, such as <Image View On> and <Play>, bring another device out of the Standby state.
The <Give Device Power Status> message is used to determine the current power status of a target device.
The target device responds with a <Report Power Status> message containing the Power Status operand.
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Recording
Device
TV
User selects
"Switch to DVR"
<Give Device Power Status>
<Report Power Status>[ “Standby”]
<User Control Pressed>[ “Power”]
Device
starts to
Powers
on
power On
<Give Device Power Status>
<Report Power Status>
[“In transition Standby to On ”]
<Give Device Power Status>
Device
Powers on
fully On
<Report Power Status>[ “On”]
Switches to
relavent HDMI
relevant
connector
<Set Stream Path>
[Physical Address of DVR]
<Active Source>
CEC Figure 25 A typical scenario for to discover the power status of a target device
Some devices, such as a Recording Device, may take some time before they have fully transitioned to the On
state. A requesting device may poll the target device to determine when that device is fully On. In this case,
the requesting device shall not send a <Give Device Power Status> message more frequently than once
every 0.5 seconds. It is not recommended that a requesting device polls another device until the first device
has transitioned to a stable state.
CEC 13.14.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
When sending this Message
From Version 1.3a
Device
To Version 1.2a or
1.3 Device
Possible behavior
<Give Device Power Status>
Any
Any (except CEC
Switches)
Device may respond with a <Feature
Abort> message as this was optional
in 1.3 and before
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CEC 13.15
Version 1.4b
System Audio Control
CEC 13.15.1
Messages
The following messages are used for the System Audio Control feature:
<Give Audio Status>, <Give System Audio Mode Status>, <Report Audio Status>, <Report Short Audio
Descriptor>, <Request Short Audio Descriptor>, <Set System Audio Mode>, <System Audio Mode Request>,
<System Audio Mode Status>, <User Control Pressed>, <User Control Released>.
For details of which messages are mandatory, see CEC Table 23, CEC Table 27 and CEC Table 28.
CEC 13.15.2
Feature Description
This feature allows an Amplifier to provide the audio for a source that is being displayed on a TV. When in
this mode, the Amplifier uses the same source as the video and provides the volume control function, instead
of the TV, which mutes its speakers.
The feature can be initiated from a device (e.g. TV or STB) or the Amplifier. In the case of initiation by a
device other than the Amplifier, that device sends a <System Audio Mode Request> message to the Amplifier,
with the Physical Address of the device that it wants to use as a source as an operand. Note that the Physical
Address may be the TV or STB itself. The Amplifier comes out of the Standby state (if necessary) and
switches to the relevant input connector (see below concerning alternative connections). The Amplifier shall
then respond by sending a <Set System Audio Mode> [“On”] message – see below about addressing mode
(direct or broadcast) of this command.
User initiates
the feature on TV
TV
Amplifier
<System Audio Mode Request> [Physical Address]
Comes out of Standby if necessary
Switches to relevant input for device
at [Physical Address]
<Set System Audio Mode> [“On”] broadcast
Mutes its
speakers
Unmutes its
speakers
CEC Figure 26 A typical scenario for initiating the System Audio Control feature from a TV
When the feature is initiated from the Amplifier, it shall come out of the Standby state (if necessary) and then
shall discover which device is the currently active source, by broadcasting a <Request Active Source>
message (note that it is not necessary for the Amplifier to send a <Request Active Source> message if the
Amplifier already knows the source or if System Audio Control is not required). The active device shall
respond with an <Active Source> message with its Physical Address and the Amplifier then selects the
relevant input for that device. The Amplifier then starts the feature by sending a broadcast or directly
addressed <Set System Audio Mode> [“On”] message as described below.
The <Set System Audio Mode> [“On”] message shall initially be directly addressed to the TV when a device
other than the TV (e.g. Amplifier or STB) has initiated the feature and if the Amplifier does not know and
needs to confirm that the TV is present and that it supports the feature (for exception see CEC 13.15.4.2 - 3).
Once the Amplifier has successfully discovered the TV and verified support for the Feature, the message
does not need to be sent at the further initiations until the Amplifier is put into the Standby state.
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If the TV is not present or it does not implement the message (i.e. it does not ACK the message, or it replies
with a <Feature Abort> [“Unrecognized opcode”] message, i.e., it does not implement this message), then the
Amplifier does not proceed further with the feature (for exception see CEC 13.15.4.2 - 3). Note that the
Amplifier needs to wait for the required maximum response time specified in CEC 9.2 before deciding that a
response has not come from the TV.
Note: an Amplifier or a TV conforming to Version 1.4 or later is not required to change its mute/unmute state
on receipt of a directly addressed <Set System Audio Mode> [“On”] message. A TV conforming to Version
1.3a may mute its speakers on receipt of a directly addressed <Set System Audio Mode> [“On”] message.
If the TV does not reply with a <Feature Abort> message, then the Amplifier broadcasts a
<Set System Audio Mode> [“On”] message to inform any other devices (e.g. STBs) that the feature has been
started. Further <Set System Audio Mode> [“On”] messages may use the broadcast address, until the
Amplifier is put into the Standby state. It is not recommended for the Amplifier to store the fact that a TV
supports this feature since this does not allow the Amplifier to detect if the TV has been changed to a device
that does not support this feature.
CEC Figure 27 A typical scenario for initiating the System Audio Control feature from an Amplifier
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CEC Figure 28 A typical scenario for initiating the System Audio Control feature from a STB
When the Amplifier broadcasts the <Set System Audio Mode> [“On”] message, it shall unmute its speakers.
When the TV receives the <Set System Audio Mode> [“On”] broadcast message, it shall mute its speakers.
Stopping the feature can be initiated from the Amplifier or other device. When the non-Amplifier device (e.g.
TV or STB) wants to stop the feature, it sends a <System Audio Mode Request> message without a
parameter to the Amplifier. The Amplifier shall respond by broadcasting a <Set System Audio Mode> [“Off”]
message.
CEC Figure 29 A typical scenario terminating the System Audio Control feature from a TV or STB
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The Amplifier can terminate the feature by broadcasting a <Set System Audio Mode> [“Off”] message.
CEC Figure 30 A typical scenario terminating the System Audio Control feature from the Amplifier
When the Amplifier broadcasts the <Set System Audio Mode> [“Off”] message, it shall mute its speakers.
When the TV receives the <Set System Audio Mode> [“Off”] broadcast message, it shall unmute its speakers.
When the System Audio Mode is On, the volume can be set using the volume control of the Amplifier or other
devices which have a volume control, such as the TV or a STB, using either the relevant user remote control
or local controls on the device (e.g. physical Volume + / - keys or a rotary style control). Similarly, the mute
status of the Amplifier can be controlled by the relevant “mute” remote control button (or other controls) of the
various devices.
CEC Figure 31 Typical Operation of the volume control where the user presses and quickly releases a key
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CEC Figure 32 An example of TV and Amplifier implementing Press and Hold behavior
Whenever the volume is changed by one of the above methods and the System Audio Mode is On, the
device that received the User’s volume commands sends out a <User Control Pressed> with the relevant
[“Volume Up”] or [“Volume Down”] operand to the Amplifier. When the User releases the control, the device
sends a <User Control Released> message to the Amplifier. For further information on the User Control
messages, press and hold, timing, etc, see CEC 13.13.
Note that the behavior of the volume function will be determined by the behavior of the Amplifier’s volume
control.
When the user requires to mute or unmute the Amplifier’s speakers while the System Audio Mode is On, the
device (such as a TV or STB) sends a <User Control Pressed> message with an operand of [“Mute”]. The
behavior of this [“Mute”] message is determined by the Amplifier. Alternatively, the device (such as a TV or
STB) may send a <User Control Pressed> message with an operand of [“Mute Function”] or ["Restore
Volume Function"] (see CEC 13.15.4.5 for further information).
The <Give Audio Status> and <Report Audio Status> messages are mainly used so that the TV can display
the audio status of the external Amplifier, for instance the current Mute status or a Volume level display. The
<Give Audio Status > message is used to ask for the current audio status of a target Amplifier. The target
device responds by sending a <Report Audio Status> message containing the Audio Status operand back to
the device which sent the <Give Audio Status>.
After the relevant <User Control Pressed> message has been sent to adjust the volume, the Amplifier may
send <Report Audio Status> messages so that the TV may display updated volume indication as the volume
changes. In this case, it is not recommended to send a <Report Audio Status> message more frequently than
once every 500ms.
When the Amplifier is muted or unmuted, it should send a <Report Audio Status> message so that the TV
may display the updated mute status.
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While System Audio Mode is On:
the TV or source shall not change their own internal volume levels;
the Amplifier’s local and remote controls shall also be active and able to control its volume.
If the System Audio Mode is On, then the Amplifier shall send a <Set System Audio Mode> [“Off”] message
just before it goes into the Standby state in order to restore the volume function back to the TV.
When a TV or other source which implements the System Audio Control feature comes out of Standby, or
activates the feature, it shall request the current System Audio Mode status by sending a
<Give System Audio Mode Status> message. The Amplifier, if active (i.e. out of the Standby state), shall
respond with a <System Audio Mode Status> message indicating the current status. The TV or source shall
behave according to the current System Audio Mode status, as described in the paragraphs above.
A TV will connect its audio to the Amplifier via an alternative connection link such as analogue, S/PDIF or
Audio Return Channel (see Supplement 2). This is because the TV is at the end of an HDMI chain and so
audio from the TV to the Amplifier must be carried by the alternative link. It is also possible that other devices
may connect their audio to the Amplifier using an alternative link. In these cases it is the responsibility of the
Amplifier to switch to the device identified at a specified Physical Address (as indicated in a <System
Audio Mode Request> or an <Active Source> message) and map that address to the actual connection in
use, i.e. an HDMI connector or an alternative connector. In the case of a TV, the Physical Address of 0.0.0.0
will need to be mapped to the relevant alternative connector on the Amplifier (e.g. analogue, Audio Return
Channel or S/PDIF). These mappings are usually made at installation time when the user identifies which
connector and connection on the Amplifier is used for each device.
CEC 13.15.3
Discovering the Amplifier’s Audio Format support
When using either an alternative link (e.g. S/PDIF) or the Audio Return Channel (see Supplement 2), the TV
may enquire if the Amplifier supports a particular audio format by sending a <Request Short Audio
Descriptor> message to the Amplifier which contains the [Audio Format ID and Code] of the requested format.
If the Amplifier supports this format, it responds with a <Report Short Audio Descriptor> message containing
the relevant [Short Audio Descriptor]. If the Amplifier does not support that format, then it responds with a
<Feature Abort> [“Invalid Operand”] message. The TV may attempt to discover if the Amplifier supports
another audio format, until a common format is discovered.
CEC Figure 33 An example of alternative connection link
The TV may also enquire if an Amplifier supports multiple audio formats by using one <Request Short Audio
Descriptor> message, up to a maximum of 4 formats. In this case, the Amplifier responds with a <Report
Short Audio Descriptor> message indicating which of the audio formats it supports, from the list in the
corresponding <Request Short Audio Descriptor> message.
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CEC Figure 34 Typical Operation to discover the Audio Format capability of an Amplifier
If the TV receives <Feature Abort> [“Invalid Operand”] messages in response to all <Request Short Audio
Descriptor> messages that it sent (since the Amplifier does not support the requested audio formats), then
the TV selects default 2 channels LPCM audio format.
CEC 13.15.4
CEC 13.15.4.1
Further behavior
Operation with legacy Amplifier
Some Amplifiers conforming to Version 1.3a might not change the mute/unmute status of their own speakers
automatically when the system audio mode is changed. It is optional for a TV’s manufacturer to try and solve
this using appropriate techniques, e.g. as in the following examples:
1. When a <Set System Audio Mode> [“On”] message is broadcast:
1-1) TV sends a <Give Audio Status> message to the Amplifier
1-2) If it is not acknowledged, or the Amplifier responds with a <Feature Abort> or the Amplifier does not
respond with a <Report Audio Status> message within the time specified in section CEC 9.2, then the TV
sends a <User Control Pressed> [“Restore Volume Function”] message to the Amplifier.
1-3) Else if the TV receives a <Report Audio Status> indicating "Audio Mute On", then the TV sends a
<User Control Pressed> [“Mute”] message to the Amplifier.
2. When a <Set System Audio Mode> [“Off”] message is broadcast:
2-1) TV sends a <Give Audio Status> message to the Amplifier
2-2) If it is not acknowledged, or the Amplifier responds with a <Feature Abort> or the Amplifier doesn't
respond with a <Report Audio Status> message within the time specified in section CEC 9.2, then the TV
sends a <User Control Pressed> [“Mute Function”] message to the Amplifier.
2-3) Else if the TV receives a <Report Audio Status> indicating "Audio Mute Off", then the TV sends a
<User Control Pressed> [“Mute”] message to the Amplifier.
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CEC 13.15.4.2
Version 1.4b
Operation with TVs that do not support the Feature
In order to enable the System Audio Control feature when working with TV’s that do not support the feature, it
is possible for the Amplifier to mute or disable the audio part of the signal on its HDMI output towards the TV.
In this case, if the System Audio Control Feature has been initiated by a device that is not the Amplifier and
the Amplifier is on the active path (i.e. it is on the path between the Active Source and the TV, or it is the
Active Source), then the Amplifier may broadcast a <Set System Audio Mode> [“On”] message without first
sending the directly addressed version first. However, implementers should note that when using this method
it will not be possible to have the sound available on headphones connected to the TV. This will affect people
with hearing difficulties who use headphones to hear the sound effectively.
In another case, if a non-Amplifier device such as an STB which is connected to the TV initiates a <System
Audio Mode Request> message with a parameter, the Amplifier may broadcast a <Set System Audio Mode>
["On"] message confirming the audio signal connection from the STB through the TV. The Amplifier mutes the
TV e.g. by sending <User Control Pressed>["Mute"] or <User Control Pressed>["Mute Function"].
CEC 13.15.4.3
Audio-only use
Some use cases do not require the TV to display video. Some examples are:
•
listening to radio tuner (built in the Amplifier);
• a STB playing a radio channel which is connected to the Amplifier (either via HDMI, Audio Return
Channel or an alternative connection) and where there is no suitable or interesting video to display;
If the user operates volume/mute controls of another device (e.g. TV or STB), it is recommended that these
control events are sent to the Amplifier. To achieve this, in such "audio-only" use cases, the Amplifier needs
to broadcast a <Set System Audio Mode> [“On”] message. This message informs the other devices of the
state of System Audio Mode and helps them to determine the proper Destination for the volume control key
events.
In these cases, the Amplifier needs to broadcast a <Set System Audio Mode> [“On”] message without first
checking that the TV supports the System Audio Control Feature or not.
Note – this is an optional feature.
CEC 13.15.4.4
Power State Changes
If the Amplifier comes out of the Standby state as a result of an action other than receiving a <System Audio
Mode Request> message, then it is a decision for the Amplifier's manufacturer as to whether the Amplifier
starts the System Audio Mode or not.
For instance, the Amplifier manufacturer may decide that System Audio Mode is On because the user has
turned on the Amplifier, or the Amplifier may remember the previous state before going to Standby, or the
user has set startup states.
If the Amplifier decides to start the System Audio Mode (after checking that the TV supports the feature and
is present as described in the above sections), the Amplifier shall broadcast a <Set System Audio
Mode>["On"] message to inform the other devices.
If the Amplifier decides not to start System Audio Mode, the Amplifier may broadcast a <Set System Audio
Mode>["Off"] message to confirm this state to the other devices.
CEC 13.15.4.5
Usage of remote control pass through
When a device such as TV or STB offers a deterministic mute control mechanism and the user operates this
mechanism in order to deterministically mute or unmute the Amplifier’s speakers while the System Audio
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Mode is On, the device (such as a TV or STB) sends a <User Control Pressed> message with an operand of
[“Mute Function”] or ["Restore Volume Function"]. Note that the Amplifier shall support a <User Control
Pressed> message with an operand of ["Mute"], and may support a <User Control Pressed> message with
an operand of [“Mute Function”] and ["Restore Volume Function"].
If the System Audio Mode is Off and the Amplifier receives a volume control (i.e.. Volume Up, Volume Down
or Mute) from its own remote control or local keypresses for, it is up to Amplifier manufacturer’s
implementation to either consume the keys in the Amplifier or forward the keypresses to the TV.
If a device such as a STB with volume control receives own remote control or local key keypresses for
volume control, it is up to STB manufacturer's implementation to either consume the keys in the STB or
forward the keypresses. This choice can be dependent upon the state of the STB. In case of forwarding the
STB sends those keypresses either to the Amplifier or to the TV, depending on whether System Audio Mode
is On (send to Amplifier) or Off (send to TV).
Note – when the System Audio Mode is Off, a TV might not support volume control using <User Control
Pressed> messages (i.e. Volume Up, Volume Down or Mute).
CEC 13.15.5
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.4.
TVs and Amplifiers conforming to Version 1.3a may mute / unmute their speakers on receiving a directly
addressed <Set System Audio Mode> message instead of the broadcast message.
Audio connection using ARC (Audio Return Channel) is new in Version 1.4.
<Request Audio Descriptor> and <Report Audio Descriptor> are new messages in Version 1.4 and Followers
conforming to Version 1.3a or earlier will respond with a <Feature Abort> to these messages.
This feature was introduced in Version 1.3a. Devices conforming to Version 1.3 or earlier will respond with a
<Feature Abort> to all directly addressed messages sent by an Initiator for this feature.
CEC 13.16
Audio Rate Control
CEC 13.16.1
Messages
The following messages are used for the Audio Rate Control Feature:
<Set Audio Rate>
For details of which messages are mandatory, see CEC Table 24, CEC Table 27 and CEC Table 28.
CEC 13.16.2
Feature Description
This feature allows the audio playback rate of a Source Device to be controlled by another device, e.g. an
Audio System. A device may control the audio rate from a Source Device by sending a directly addressed
<Set Audio Rate> message. Audio Rate Control is an exclusive function so that the Source Device can only
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be controlled by the one device that sent the <Set Audio Rate> message which started the Audio Rate
Controlled function. It shall ignore any <Set Audio Rate> messages from other devices whilst it is in that state.
The audio rate controlled state is left when the controlling device sends a <Set Audio Rate> message with
[Audio Rate] = “Rate Control Off” to the Source Device. The controlling device should send a
<Set Audio Rate> command at least once every 2 seconds for active sensing. If a <Set Audio Rate>
message is not received within 2 seconds or the status of the Source Device changes internally, then the
Source Device shall quit the audio rate controlled mode. There are two control ranges, Wide and Narrow.
When set to a specific range, the Source Device shall keep audio data streaming continuously even during a
rate change transition, e.g. from Standard Rate to Fast Rate.
CEC 13.16.3
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.3a.
This feature was introduced in Version 1.3a. Devices conforming to Version 1.3 or earlier will respond with a
<Feature Abort> message to all messages sent by an Initiator for this feature.
CEC 13.17
Audio Return Channel Control
CEC 13.17.1
Messages
The following messages are used for the Audio Return Channel Control feature (see Supplement 2):
<Initiate ARC>, <Report ARC Initiated>, <Report ARC Terminated>, <Request ARC Initiation>, <Request
ARC Termination>, <Terminate ARC>
For details of which messages are mandatory, see CEC Table 25, CEC Table 27 and CEC Table 28.
CEC 13.17.2
Feature description
This feature allows an Audio Return Channel receiver (ARC Rx) device to initiate or terminate an Audio
Return Channel between an adjacent Audio Return Channel transmitter (ARC Tx) device and itself. In
contrast, the ARC Tx device is allowed to request an adjacent ARC Rx device to initiate or terminate an
Audio Return Channel between the devices. Both adjacent devices shall only utilize audio data transmissions
via the Audio Return Channel between devices after the negotiation and confirmation between them has
been successfully completed by following the procedures specified in this section.
CEC Figure 35 An example of topology with ARC link
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If a Follower receives a message for this feature from a non-adjacent Initiator or never supports this feature
with the Initiator on the relevant link (the Follower may support this feature on another link), then the Follower
may respond with a <Feature Abort> [“Refused”] message.
Note - Messages for Audio Return Channel Control provide connection functionality, and do not control
selection of the audio source.
CEC 13.17.2.1
Initiation and Termination from ARC Rx device
In the case of initiation, an ARC Rx device shall send a directly addressed <Initiate ARC> message to an
adjacent device after the ARC Rx functionality (see Supplement 2) has been activated. If the Follower sends
a <Feature Abort> [“Unrecognized opcode”] message or no related message within the required maximum
response time specified in CEC 9.2, then the ARC Rx device assumes that the Follower does not support the
Audio Return Channel feature.
If the Follower is an ARC Tx device, it shall respond by sending a directly addressed <Report ARC Initiated>
message or <Report ARC Terminated> message or <Feature Abort> message within the required maximum
response time specified in CEC 9.2. Note – for example, if the Follower is an ARC Tx device, it may send a
<Feature Abort> [“Cannot provide source”] message if there is no audio stream to output.
If the Follower responds with a directly addressed <Report ARC Initiated> message, the ARC Rx device
knows that the Follower is an ARC Tx device, its ARC Tx functionality (see Supplement 2) has been activated
and it transmits an audio stream via the Audio Return Channel. If the Follower responds with a directly
addressed <Report ARC Terminated> message, the ARC Rx device knows the Follower is an ARC Tx device
but its ARC Tx functionality has been deactivated and it is not transmitting an audio stream via the Audio
Return Channel. In this case, the ARC Rx device may deactivate the ARC Rx functionality.
CEC Figure 36 Initiation and Termination from ARC Rx device
In the case of termination, the ARC Rx device shall send a directly addressed <Terminate ARC> message to
the adjacent ARC Tx device. The ARC Tx device shall stop transmitting its audio stream, deactivate the ARC
Tx functionality and respond with a directly addressed <Report ARC Terminated> message. In this case, the
ARC Rx device may de-activate the ARC Rx functionality. If the ARC Rx device has not received a <Report
ARC Terminated> message within the required maximum response time specified in CEC 9.2, the ARC Rx
device may keep its ARC Rx functionality active or may de-activate the ARC Rx functionality by detecting the
de-activation of the ARC Tx functionality, e.g. by loss of an audio signal.
Also, in the case where the ARC Tx device has requested initiation to the adjacent ARC Rx device and the
ARC Rx device has initiated the feature (see CEC 13.17.2.2), the ARC Rx device may at any time start to
terminate the feature by sending a directly addressed <Terminate ARC> message to the ARC Tx device.
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CEC 13.17.2.2
Version 1.4b
Request from ARC Tx device
In the case where an ARC Tx device wants to initiate an Audio Return Channel, then the ARC Tx device shall
not send an <Initiate ARC> message. Instead, the ARC Tx device may request an adjacent device to initiate
the Audio Return Channel by sending a directly addressed <Request ARC Initiation> message. If the
Follower sends a <Feature Abort> [“Unrecognized opcode”] message or no message within the required
maximum response time specified in CEC 9.2, then the ARC Tx device assumes that the Follower does not
support the Audio Return Channel feature. If the Follower sends a <Feature Abort> [“Not in correct mode to
respond”] message, then the ARC Tx device assumes that the follower is an ARC Rx device and is not ready
to initiate the Audio Return Channel feature.
If the Follower is an ARC Rx device, then when it is ready to initiate the feature it shall start the initiation
sequence as described in CEC 13.17.2.1.
CEC Figure 37 Request from ARC Tx device
In the case where an ARC Tx device wants to terminate an Audio Return Channel, then the ARC Tx device
shall not send a <Terminate ARC> message. Instead, the ARC Tx device may request the adjacent ARC Rx
device to terminate the Audio Return Channel by sending a directly addressed <Request ARC Termination>
message.
When the ARC Rx device is ready to terminate the Audio Return Channel, the ARC Rx device shall start the
termination sequence as described in CEC 13.17.2.1.
If the ARC Rx device sends a <Feature Abort> message, or no related message is received within the
required maximum response time specified in CEC 9.2, the ARC Tx device may de-activate the ARC Tx
functionality.
If the ARC Tx device is temporarily entering a state where it cannot terminate the Audio Return Channel, it
shall request termination before entering that state by sending a directly addressed <Request ARC
Termination> message to the adjacent ARC Rx device.
Also, in the case where the ARC Rx device has initiated this feature (see CEC 13.17.2.1), the adjacent ARC
Tx device may request termination of the feature to the ARC Rx device.
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CEC 13.17.3
Version 1.4b
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.4.
This is a new Feature in Version 1.4. Devices conforming to Version 1.3a or earlier will respond with a
<Feature Abort> to all messages sent by an Initiator for this feature.
CEC 13.18
Capability Discovery and Control for HEC
CEC 13.18.1
Introduction and Messages
Supplement 2 describes the HDMI Ethernet Channel (HEC). HEC needs some messages for control and
discovery, called Capability Discovery and Control (CDC). These CDC messages are broadcast CEC
messages and share a single CEC opcode. CDC messages may be used by both CDC only devices and
CDC devices with CEC.
CEC 13.18.2
CDC only Device
A device that uses only CDC messages (but no further CEC messages) takes logical address 15
(Unregistered) as an initiator when it sends messages. Such a CDC only device does not need to implement
the mandatory CEC messages, but adheres to the low level CEC protocol with some extensions, as specified
in Supplement 2.
CEC 13.18.3
CDC Device with CEC
If a device implements CDC messages and at least one further CEC message, the device shall also
implement all the mandatory CEC messages for its device type(s), see CEC Table 8 to CEC Table 26, CEC
Table 27 and CEC Table 28, and shall attempt to allocate a relevant Logical Address according to section
CEC 10.
CEC 13.18.4
Behavior with Earlier Versions
There is no change in behavior for this Feature between Version 1.4b and Version 1.4.
This is a new Feature in Version 1.4. Devices conforming to Version 1.3a or earlier will ignore all CDC
messages (since CDC messages are broadcast, they will not respond with a <Feature Abort> message on
receiving a CDC message).
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CEC 14
Version 1.4b
Device States
This section shows how CEC messages can change the states of a device.
CEC 14.1.1
Device States
The following is a list of states that each device type can be in. Each device should be in one and only one
state for each line shown below.
All Devices:
On, Standby, Off
TV:
Image Display, Menu Display, Text Display
Device Menu Active, Device Menu Inactive
Recording Device:
Recording, Not Recording
Playback Device:
Deck Active, Deck Inactive
Menu Providing Device:
Device Menu Active, Device Menu Inactive
CEC 14.1.2
State Changes
The following diagrams show the state transitions that are caused as a direct result of a device receiving a
CEC message. Transitions between states that are not caused as a result of CEC messages are generally
not shown, except where no CEC message can cause that transition.
CEC 14.1.3
All Devices
<Standby>
On
Standby
Any message which can bring a device out of standby, e.g. <Image View On>
CEC 14.1.4
TV
<Image View On>, <Text View On>
Text Display
Image Display
User Selects Teletext, EPG etc.
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<Text View On>
Menu Display
Image Display
User Selects Menu
<Menu Status> ["Activated"]
Device Menu
Active
Device Menu
Inactive
<Menu Status> ["Deactivated"]
CEC 14.1.5
Recording Device
<Record On> (Recording Possible)
Not Recording
Recording
<Record Off>
CEC 14.1.6
Playback Device
<Deck Control> ["Skip Fwd / Wind"], <Deck Control> ["Skip Back / Rewind"]
(Device Dependant and Media Available)
<Play> (Media Available)
Deck Inactive
Deck Active
<Deck Control> ["Skip Fwd / Wind"],
<Deck Control> ["Skip Back / Rewind"]
<Deck Control> ["Stop"], <Deck Control> ["Eject"]
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CEC 14.1.7
Version 1.4b
Menu Providing Device
<Menu Request> ["Activated"]
Device Menu
Inactive
Device Menu
Active
<Menu Request> ["Deactivated"]
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CEC 15
Version 1.4b
Message Descriptions
The section defines the individual messages used in CEC. It describes them and defines their parameters
and expected responses. As CEC has no session layer, this section and the operands section (CEC 17)
effectively define the complete messaging system. Tables CEC Table 8 to CEC Table 26 show which
messages are mandatory. If a manufacturer implements any of the optional messages, then they shall be
implemented as described in CEC 13.
The following list describes each heading within the message tables CEC Table 8 to CEC Table 26.
Opcode – The name used to identify the message.
Value – The unique identifier for the message.
Description – A brief description of the message.
Parameters – The set of parameters used by the message, refer to CEC Table 29 for individual
descriptions.
Parameter Description – A brief description of the parameters that the message uses.
Response – Describes how a device should respond on receipt of the message.
Directly Addressed – Indicates if the message may be directly addressed.
Broadcast – Indicates if the message may be broadcast.
Mandatory – Indicates if it is mandatory for a device to react and respond on receipt of the message.
Note that where a message is indicated as being mandatory for ‘All’ devices, this excludes devices
which act only as a CEC Switch.
Within the table some cells are intentionally left blank; this indicates that there are no associated
requirements for the Opcode described.
In tables CEC Table 8 to CEC Table 26 “TV” refers to the device using Logical Address TV (0).
CDC only devices which do not implement other CEC messages (see section CEC 13.18.2), shall not
implement messages that are indicated as Mandatory in CEC Table 8 to CEC Table 26. However, CDC
devices with CEC shall implement the messages indicated in section CEC 13.18.3.
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CEC Table 8 Message Descriptions for the One Touch Play Feature
Opcode
value
Description
Parameters
Parameter description
Response
1
0x82
Used by a new source
to indicate that it has
started to transmit a
stream OR used in
response to a
<Request Active
Source>
[Physical Address]
The Physical Address
of the device.
A current active source
should take appropriate
action.
TV should switch to the
appropriate input.
Any CEC switches
between source and root
shall switch to the
appropriate input and
come out of the Standby
state if necessary.
<Image View On>
0x04
Sent by a source
device to the TV
whenever it enters the
active state
(alternatively it may
send <Text View On>).
None
Turn on (if not on). If in
‘Text Display’ state then
the TV enters ‘Image
Display’ state.
Note: Should not change
TV menu or PIP status.
<Text View On>
0x0D
As <Image View On>,
but should also remove
any text, menus and
PIP windows from the
TV’s display.
None
As <Image View On>, but
should remove PIPs and
menus from the screen.
The TV enters ‘Image
Display’ state regardless
of its previous state.
<Active Source>
1
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
All
sources
TV, CEC
Switches
All
sources
shall
implement
at least
one of
<Image
View On>
or <Text
View On>
TV
All
sources
shall
implement
at least
one of
<Image
View On>
or <Text
View On>
TV
This message is also used in the Routing Control Feature
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Page CEC-72 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 9 Message Descriptions for the Routing Control Feature
Opcode
value
Description
Parameters
Parameter description
Response
0x82
Used by a new source
to indicate that it has
started to transmit a
stream OR used in
response to a
<Request Active
Source>
[Physical Address]
The Physical Address
of the device.
A current active source
should take appropriate
action.
TV should switch to the
appropriate input.
Any CEC switches
between source and root
shall switch to the
appropriate input and
come out of the Standby
state if necessary.
<Inactive Source>
0x9D
Used by the currently
active source to inform
the TV that it has no
video to be presented
to the user, or is going
into the Standby state
as the result of a local
user command on the
device.
[Physical Address]
The Physical Address
of the device.
The TV may display its
own internal tuner and
shall send an <Active
Source> with the address
of the TV; or
The TV may send <Set
Stream Path> to another
device for display.
<Request Active
Source>
0x85
Used by a new device
to discover the status
of the system.
None
<Active Source>
2
2
<Active Source> from the
currently active source.
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
All
sources
TV, CEC
Switches
This message is also used in the One Touch Play Feature
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Page CEC-73 of 127
All,
except for
CEC
Switches
and
devices
which
cannot
become a
source.
High-Definition Multimedia Interface Specification
Version 1.4b
CEC
Switches
and TV
with 2 or
more
HDMI
inputs.
CEC
Switches
If a CEC Switch is at the
specified address it shall
send a <Routing
Information> message to
indicate its current active
path.
CEC
Switches,
except for
root
device at
0.0.0.0
CEC
Switches
Any CEC switches
between the TV and the
source device shall switch
inputs according to the
path defined in [Physical
Address]. A CEC device
at the new address
should come out of the
Standby state, stream its
output and broadcast an
<Active Source>
message.
Description
Parameters
Parameter description
Response
<Routing Change>
0x80
Sent by a CEC Switch
when it is manually
switched to inform all
other devices on the
network that the active
route below the switch
has changed.
[Original Address]
[New Address]
The previous address
that the switch was
switched to and the
new address it has
been moved to.
If a CEC Switch is at the
new address, it sends a
<Routing Information>
message to indicate its
current active route.
<Routing
Information>
0x81
Sent by a CEC Switch
to indicate the active
route below the switch.
[Physical Address]
The current active route
to the sink in the CEC
Switch.
<Set Stream Path>
0x86
Used by the TV to
request a streaming
path from the specified
Physical Address.
[Physical Address]
The Physical Address
of the source device.
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Broadcast
Mandatory
for Follower
value
HDMI Licensing, LLC
Directly
addressed
Mandatory
for Initiator
Opcode
Page CEC-74 of 127
CEC
Switches
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 10 Message Descriptions for the Standby Feature
Opcode
value
Description
Parameters
<Standby>
0x36
Switches one or all
devices into the
Standby state. Can be
used as a broadcast
message or be
addressed to a specific
device.
None
Parameter description
Response
Switch the device into the
3
Standby state.
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
TV
(Broadcast
Address)
All
Ignore the message if
already in the Standby
state.
See section CEC 13.3
for important notes on
the use of this message
3
Can be ignored if actively engaged in a recording or providing a source stream for a recording. See also CEC 13.3 for other exceptions.
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High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 11 Message Descriptions for the One Touch Record Feature
Opcode
value
Description
Parameters
<Record Off>
0x0B
Requests a device to
stop a recording.
None
Parameter description
Exit ‘Recording’ state.
<Record On>
0x09
Attempt to record the
specified source.
[Record Source]
Source to record, either
analogue service,
digital service, external
source or own source
(i.e. currently selected
source).
<Record Status>
0x0A
Used by a Recording
Device to inform the
Initiator of the message
<Record On> about its
status.
[Record Status
Info]
The recording status of
the device.
Request by the
Recording Device to
record the presently
displayed source.
None
<Record TV
Screen>
0x0F
HDMI Licensing, LLC
Response
Enter ‘Recording’ state
and start recording if
possible. Send the
Initiator <Record Status>.
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
Device
Initiating a
recording
Recording
Device if
Recording
Device if
Device
Initiating a
recording
implementing
<Record
On>
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<Record
On>
Initiate a recording using
the <Record On>
message, or send a
<Feature Abort> [“Cannot
provide source”] if the
presently displayed
source is not recordable.
implementing
Page CEC-76 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 12 Message Descriptions for the Timer Programming Feature
Directly
addressed
Opcode
value
Description
Parameters
Parameter description
Response
<Clear Analogue
Timer>
0x33
Used to clear an
Analogue timer block of
a device.
See <Set
Analogue Timer>
message.
See <Set Analogue
Timer> message.
Clear timer block if
possible, then respond
with <Timer Cleared
Status>
<Clear Digital
Timer>
0x99
Used to clear a Digital
timer block of a device.
See <Set Digital
Timer> message
See <Set Digital Timer>
message
Clear timer block if
possible, then respond
with <Timer Cleared
Status> message.
<Clear External
Timer>
0xA1
Used to clear an
External timer block of
a device.
See <Set External
Timer> message
See <Set External
Timer> message
Clear timer block if
possible, then respond
with <Timer Cleared
Status> message.
<Set Analogue
Timer>
0x34
Used to set a single
timer block on an
Analogue Recording
Device.
[Day of Month]
[Month of Year]
[Start Time]
[Duration]
[Recording
Sequence]
[Analogue
Broadcast Type]
[Analogue
Frequency]
[Broadcast
System]
A complete set of
Analogue timer
information for one
recording.
<Timer Status> message.
<Set Digital Timer>
0x97
Used to set a single
timer block on a Digital
Recording Device.
[Day of Month]
[Month of Year]
[Start Time]
[Duration]
[Recording
Sequence]
[Digital Service
Identification]
A complete set of
Digital timer information
for one recording.
<Timer Status> message.
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Broadcast
Mandatory
for Initiator
Page CEC-77 of 127
Mandatory
for Follower
High-Definition Multimedia Interface Specification
Version 1.4b
Directly
addressed
Opcode
value
Description
Parameters
Parameter description
Response
<Set External
Timer>
0xA2
Used to set a single
timer block to record
from an external
device.
[Day of Month]
[Month of Year]
[Start Time]
[Duration]
[Recording
Sequence]
[External Source
Specifier]
[External Plug] |
[External Physical
Address]
A complete set of
External timer
information for one
recording.
<Timer Status> message.
<Set Timer Program
Title>
0x67
Used to set the name
of a program
associated with a timer
block. Sent directly
after sending a <Set
Analogue Timer> or
<Set Digital Timer>
message. The name is
then associated with
that timer block.
[Program Title
String]
Program title
Recording device stores
title for future reference.
Ignore message if it is not
the immediate next
message from this
Initiator following a <Set
Analogue Timer> or <Set
Digital Timer> message.
<Timer Cleared
Status>
0x43
Used to give the status
of a <Clear Analogue
Timer>, <Clear Digital
Timer> or <Clear
External Timer>
message.
[Timer Cleared
Status Data]
Indicates if the timer
was cleared
successfully.
If the message indicates
that the timer was not
cleared because there
was no matching entry,
the device should remove
the timer block locally.
<Timer Status>
0x35
Used to send timer
status to the Initiator of
a <Set Timer>
message.
[Timer Status Data]
Indicates the timer
status
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Broadcast
Mandatory
for Initiator
Page CEC-78 of 127
Mandatory
for Follower
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 13 Message Descriptions for the System Information Feature
Opcode
value
Description
Parameters
Parameter description
<CEC Version>
0x9E
Used to indicate the
version number of the
CEC Specification
which was used to
design the device, in
response to a <Get
CEC Version>.
[CEC Version]
A value indicating the
version number of the
CEC Specification
which was used to
design the device.
<Get CEC Version>
0x9F
Used by a device to
enquire which version
number of the CEC
Specification was used
to design the Follower
device.
None
<Give Physical
Address>
0x83
A request to a device to
return its Physical
Address.
<Get Menu
Language>
0x91
Sent by a device
capable of character
generation (for OSD
and Menus) to a TV in
order to discover the
currently selected
Menu language on the
TV.
Response
Directly
addressed
Broadcast
Mandatory
for Initiator
4
5
The source responds with
a <CEC Version>
message indicating the
version number of the
CEC Specification which
was used to design the
Follower device.
6
7
None
<Report Physical
Address>
All,
except for
CEC
Switches
using
Logical
Address
15
None
The TV responds with a
<Set Menu Language>
message
TV with
OSD /
Menu
generation
capabilities
4
This message is also used in the Vendor Specific Command Feature - see CEC Table 16 for requirements
This message is also used in the Vendor Specific Command Feature - see CEC Table 16 for requirements
6
This message is also used in the Vendor Specific Command Feature - see CEC Table 16 for requirements
7
This message is also used in the Vendor Specific Command Feature - see CEC Table 16 for requirements
5
HDMI Licensing, LLC
Mandatory
for Follower
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Page CEC-79 of 127
High-Definition Multimedia Interface Specification
Opcode
value
Version 1.4b
Description
Parameters
-
Used by any device for
device discovery –
similar to ping in other
protocols.
None
<Report Physical
Address>
0x84
Used to inform all other
devices of the mapping
between physical and
Logical Address of the
Initiator.
[Physical Address]
[Device Type]
The device’s Physical
Address within the
cluster.
<Set Menu
Language>
0x32
Used by a TV to
indicate its currently
selected menu
language.
[Language]
TheTV’s current menu
language.
<Polling Message>
Parameter description
Response
Shall set a low level ACK.
Set the menu language as
specified, if possible.
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
All except
for CEC
Switches
All except
for CEC
switches
All
TV
TV
All,
except for
those
devices
mentioned
in note
below.
Note: <Set Menu Language> is Mandatory as a Follower except for the following: TV, CEC Switches, Mobile Devices, other devices which are not
able to change the language by CEC messages, e.g. a PC, and devices without OSD/ Menu generation capabilities.
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High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 14 Message Descriptions for the Deck Control Feature
Opcode
value
Description
Parameters
Parameter description
Response
<Deck Control>
0x42
Used to control a
device’s media
functions.
[Deck Control
Mode]
The deck control
requested.
Perform the specified
actions, or return a
<Feature Abort>
message. It is device
dependent whether or not
a Skip Forward/Wind or
Skip Backward /Rewind
command is legal when in
the ‘Deck Inactive’ state. If
the device is in the
Standby state and it
receives an eject
command, it should power
on and eject its media.
<Deck Status>
0x1B
Used to provide a
deck’s status to the
Initiator of the <Give
Deck Status>
message.
[Deck Info]
Information on the
device’s current status.
<Give Deck Status>
0x1A
Used to request the
status of a device,
regardless of whether
or not it is the current
active source.
[Status Request]
Allows the Initiator to
request the status once
or on all future state
changes. Or to cancel a
previous <Give Deck
Status> [“On”] request.
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Directly
addressed
Broadcast
Mandatory
for Initiator
<Deck Status>
Page CEC-81 of 127
Mandatory
for Follower
High-Definition Multimedia Interface Specification
<Play>
0x41
Used to control the
playback behavior of a
source device.
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[Play Mode]
Version 1.4b
Play mode required.
Confidential
Perform the specified
actions, or return a
<Feature Abort>
message. If media is
available the device
enters ‘Deck Active’ state.
If the device is in the
Standby state, has media
available and the
parameter is [“Play
Forward”] it should power
on.
Page CEC-82 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 15 Message Descriptions for the Tuner Control Feature
Directly
addressed
Opcode
value
Description
Parameters
Parameter description
Response
<Give Tuner Device
Status>
0x08
Used to request the
status of a tuner
device.
[Status Request]
Allows the Initiator to
request the status once
or on all future state
changes, or to cancel a
previous <Give Tuner
Device Status> [“On”]
message.
Respond with a <Tuner
Device Status> message,
or stop reporting changes
on receipt of the [“Off”]
message.
<Select Analogue
Service>
0x92
Directly selects an
Analogue TV service
[Analogue
Broadcast Type]
[Analogue
Frequency]
[Broadcast
System]
Defines Broadcast
Type, Frequency and
System for an Analogue
TV service
Change to the selected
analogue service and
stream its output on the
HDMI connection. If the
tuner device is not
capable of selecting this
service, respond with a
<Feature Abort>
<Select Digital
Service>
0x93
Directly selects a
Digital TV, Radio or
Data Broadcast Service
[Digital Service
Identification]
Defines Digital TV
system and necessary
data to specify a
service
Change to the selected
digital service and stream
its output on the HDMI
connection. If the tuner
device is not capable of
selecting this service,
respond with a <Feature
Abort>
<Tuner Device
Status>
0x07
Use by a tuner device
to provide its status to
the Initiator of the
<Give Tuner Device
Status> message.
[Tuner Device Info]
Information on the tuner
devices current status.
<Tuner Step
Decrement>
0x06
Used to tune to next
lowest service in a
tuner’s service list. Can
be used for PIP.
None
Follower tunes to next
lowest service in its
service list.
<Tuner Step
Increment>
0x05
Used to tune to next
highest service in a
tuner’s service list. Can
be used for PIP.
None
Follower tunes to next
highest service in its
service list.
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Broadcast
Mandatory
for Initiator
Page CEC-83 of 127
Mandatory
for Follower
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 16 Message Descriptions for the Vendor Specific Commands Feature
Opcode
value
Description
Parameters
Parameter description
0x9E
Used to indicate the
version number of the
CEC Specification
which was used to
design the device, in
response to a <Get
CEC Version>
[CEC Version]
A value indicating the
version number of the
CEC Specification
which was used to
design the device.
<Device Vendor ID>
0x87
Reports the vendor ID
of this device.
[Vendor ID]
The vendor ID of the
device.
9
0x9F
Used by a device to
enquire which version
number of the CEC
Specification was used
to design the Follower
device.
None
<CEC Version>
8
<Get CEC Version>
8
9
Response
Directly
addressed
Broadcast
Any other interested
device may store the
vendor ID of the device.
The source responds with
a <CEC Version>
message indicating the
version number of the
CEC Specification which
was used to design the
Follower device.
Mandatory
for Initiator
Mandatory
for Follower
All devices
that want to
be able to
use the
<Vendor
Command>
message
from
specific
other
vendors.
All devices
that want to
be able to
use the
<Vendor
Command>
message
from
specific
other
vendors.
As needed
for
Devices
supporting
Vendor
Specific
Commands
As needed
for
Devices
supporting
Vendor
Specific
Commands
All devices
that want to
initiate a
scenario
with devices
of specific
other
vendors
using the
<Vendor
Command>
message.
All devices
that want to
be able to
use the
<Vendor
Command>
message
from
specific
other
vendors.
This message is also used in the System Information Feature
This message is also used in the System Information Feature
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High-Definition Multimedia Interface Specification
Opcode
value
Description
Parameters
<Give Device
Vendor ID>
0x8C
Requests the Vendor
ID from a device.
None
<Vendor
Command>
0x89
Allows vendor specific
commands to be sent
between two devices.
[Vendor Specific
Data]
<Vendor Command
With ID>
0xA0
Allows vendor specific
commands to be sent
between two devices or
broadcast.
[Vendor ID]
[Vendor Specific
data]
Version 1.4b
Parameter description
Response
Directly
addressed
Broadcast
<Device Vendor ID>
Vendor specific
command or data.
The maximum length of
the [Vendor Specific
Data] in this message
shall not exceed 14
Data Blocks.
Vendor Specific
Vendor ID of the vendor
or entity defining the
command.
Vendor specific
Vendor Specific
Mandatory
for Initiator
Mandatory
for Follower
As needed
for
Devices
which
initiate a
scenario
using the
<Vendor
Command>
message
As needed
for
Devices
supporting
Vendor
Specific
Commands
Vendor specific
command or data.
The maximum length of
[Vendor Specific Data]
in this message shall
not exceed 11 Data
Blocks.
<Vendor Remote
Button Down>
0x8A
Indicates that a remote
control button has been
depressed.
HDMI Licensing, LLC
[Vendor Specific
RC Code]
The vendor specific
Remote Control Code
for the key pressed. It is
recommended to keep
this to a minimum size.
The maximum length
shall not exceed 14
Data Blocks to avoid
saturating the bus.
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Page CEC-85 of 127
High-Definition Multimedia Interface Specification
Opcode
value
Description
Parameters
<Vendor Remote
Button Up>
0x8B
Indicates that a remote
control button (the last
button pressed
indicated by the Vendor
Remote Button Down
message) has been
released.
None
Version 1.4b
Parameter description
Response
Vendor Specific
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
Mandatory
for Initiator
Mandatory
for Follower
CEC Table 17 Message Descriptions for the OSD Display Feature
Opcode
value
Description
Parameters
Parameter description
Response
<Set OSD String>
0x64
Used to send a text
message to output on a
TV.
[Display Control]
[OSD String]
Display timing.
Text to be displayed.
TV displays the message.
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Directly
addressed
Broadcast
Page CEC-86 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 18 Message Descriptions for the Device OSD Transfer Feature
Opcode
value
Description
Parameters
<Give OSD Name>
0x46
Used to request the
preferred OSD name of
a device for use in
menus associated with
that device.
None
<Set OSD Name>
0x47
Used to set the
preferred OSD name of
a device for use in
menus associated with
that device.
[OSD Name]
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Parameter description
The preferred name of
the device.
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Response
Directly
addressed
<Set OSD Name>
Store the name and use it
in any menus associated
with that device.
Broadcast
Mandatory
for Initiator
Page CEC-87 of 127
Mandatory
for Follower
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 19 Message Descriptions for the Device Menu Control Feature
Directly
addressed
Opcode
value
Description
Parameters
Parameter description
Response
<Menu Request>
0x8D
A request from the TV
for a device to
show/remove a menu
or to query if a device
is currently showing a
menu.
[Menu Request
Type]
Indicates if the menu
request is to activate or
deactivate the devices
menu, or to simply
query the devices menu
status.
May enter or exit the
‘Device Menu Active’
state if the parameter was
“Activate” or “Deactivate”
Send <Menu Status> to
indicate the current status
of the devices menu.
<Menu Status>
0x8E
Used to indicate to the
TV that the device is
showing/has removed
a menu and requests
the remote control keys
to be passed though.
[Menu State]
Indicates if the device is
in the ‘Device Menu
Active’ state or ‘Device
Menu Inactive’ state.
If Menu State indicates
activated, TV enters
‘Device Menu Active’
state and forwards those
Remote control
commands, shown in
CEC Table 30, to the
Initiator. If deactivated, TV
enters ‘Device Menu
Inactive’ state and stops
forwarding remote control
commands.
<User Control
10
Pressed>
0x44
Used to indicate that
the user pressed a
remote control button
or switched from one
remote control button
to another. Can also be
used as a command
that is not directly
initiated by the user.
[UI Command]
Required UI command
issued by user.
Update display or perform
an action, as required.
10
Broadcast
Mandatory
for Initiator
This message is also used in the RC Passthrough and System Audio Features
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Mandatory
for Follower
High-Definition Multimedia Interface Specification
<User Control
11
Released>
0x45
Indicates that user
released a remote
control button (the last
one indicated by the
<User Control
Pressed> message).
Also used after a
command that is not
directly initiated by the
user.
Version 1.4b
None
Update display or perform
an action, as required.
CEC Table 20 Message Descriptions for the Remote Control Passthrough Feature
Directly
addressed
Opcode
value
Description
Parameters
Parameter description
Response
<User Control
12
Pressed>
0x44
Used to indicate that
the user pressed a
remote control button
or switched from one
remote control button
to another. Can also be
used as a command
that is not directly
initiated by the user.
[UI Command],
plus any necessary
Additional
Operands specified
in CEC Table 6
and CEC Table 7.
Required UI command.
Update display or perform
an action, as required.
<User Control
Released> 13
0x45
Indicates that user
released a remote
control button (the last
one indicated by the
<User Control
Pressed> message).
Also used after a
command that is not
directly initiated by the
user.
None
Update display or perform
an action, as required.
Broadcast
Mandatory
for Initiator
11
This message is also used in the RC Passthrough and System Audio Features
This message is also used in the Device Menu Control and System Audio Features
13
This message is also used in the Device Menu Control and System Audio Features
12
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Page CEC-89 of 127
Mandatory
for Follower
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 21 Message Descriptions for the Power Status Feature
Opcode
value
Description
Parameters
<Give Device Power
Status>
0x8F
Used to determine the
current power status of
a target device
None
<Report Power
Status>
0x90
Used to inform a
requesting device of
the current power
status
[Power Status]
HDMI Licensing, LLC
Parameter description
Response
<Report Power Status>
The current power
status
Confidential
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
All
(except
CEC
switches)
All
(except
CEC
switches)
Page CEC-90 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 22 Message Descriptions for General Protocol messages
Directly
addressed
Opcode
value
Description
Parameters
Parameter description
Response
<Feature Abort>
0x00
Used as a response to
indicate that the device
does not support the
requested message
type, or that it cannot
execute it at the
present time.
[Feature Opcode]
[Abort Reason]
The Opcode of the
aborted message.
The reason provides an
indication as to whether
the Follower does not
support the message,
or does support the
message but cannot
respond at the present
time.
Assume that request is
not supported or has not
been actioned.
<Abort> Message
0xFF
This message is
reserved for testing
purposes.
None
A device shall never
support this message,
and shall always respond
with a <Feature Abort>
message containing any
valid value for [Abort
Reason]. CEC switches
shall not respond to this
message.
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Broadcast
Mandatory
for Initiator
Mandatory
for Follower
Generate
if a
message
is not
supported
All
All,
except for
CEC
switches
Page CEC-91 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 23 Message Descriptions for the System Audio Control Feature
Parameter description
Response
Directly
addressed
Opcode
value
Description
Parameters
<Give Audio
Status>
0x71
Requests an Amplifier
to send its volume and
mute status
None
<Report Audio Status>
<Give System Audio
Mode Status>
0x7D
Requests the status of
the System Audio
Mode
None
Amplifier sends a
<System Audio Mode
Status> message
indicating status (On or
Off)
<Report Audio
Status>
0x7A
Reports an Amplifier’s
volume and mute
status
[Audio Status]
Volume and mute
status
<Report Short Audio
Descriptor>
0xA3
Report Audio
Capability.
[Short Audio
Descriptor]
Up to 4 Short Audio
Descriptor(s) identifying
supported audio
format(s).
<Request Short
Audio Descriptor>
0xA4
Request Audio
Capability.
[Audio Format ID
and Code]
Up to 4 [Audio Format
ID and Code] (s) (if
needed).
<Report Short Audio
Descriptor>
<Set System Audio
Mode>
0x72
Turns the System
Audio Mode On or Off.
[System Audio
Status]
Specifies if the System
Audio Mode is On or
Off.
If set to On, the TV mutes
its speakers. The TV or
STB sends relevant
<User Control Pressed>
or <User Control
Released> as necessary.
Broadcast
Mandatory
for Initiator
If set to Off, the TV
unmutes its speakers.
The TV or STB stop
sending the volumerelated <User Control
Pressed> or <User
Control Released>
messages.
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Mandatory
for Follower
High-Definition Multimedia Interface Specification
Version 1.4b
Opcode
value
Description
Parameters
Parameter description
Response
<System Audio
Mode Request>
0x70
A device implementing
System Audio Control
and which has volume
control RC buttons
(e.g. TV or STB)
requests to use
System Audio Mode to
the Amplifier
[Physical Address]
Source to be used is
the device specified at
this address.
The Amplifier comes out
of the Standby state (if
necessary) and switches
to the relevant connector
for device specified by
[Physical Address]. It then
sends a <Set System
Audio Mode> [On]
message.
Directly
addressed
Broadcast
Mandatory
for Initiator
<System Audio Mode
Request> sent without a
[Physical Address]
parameter requests
termination of the feature.
In this case, the Amplifier
sends a <Set System
Audio Mode> [Off]
message.
<System Audio
Mode Status>
0x7E
Reports the current
status of the System
Audio Mode
[System Audio
Status]
Current system Audio
Mode
If [On], the device
requesting this
information can send the
volume-related <User
Control Pressed> or
<User Control Released>
messages.
<User Control
14
Pressed>
0x44
Used to indicate that
the user pressed a
remote control button
or switched from one
remote control button
to another. Can also be
used as a command
that is not directly
initiated by the user.
[UI Command] of
“Volume Up”,
“Volume Down” or
“Mute” ,"Mute
Function", "Restore
Volume Function”.
Relevant UI command
issued by user.
Increase or Decrease the
volume of the Amplifier, or
mute/unmute the
Amplifier.
14
This message is also used in the Device Menu Control and RC Rassthrough Features
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Mandatory
for Follower
High-Definition Multimedia Interface Specification
Opcode
value
Description
Parameters
<User Control
15
Released>
0x45
Indicates that user
released a remote
control button (the last
one indicated by the
<User Control
Pressed> message).
Also used after a
command that is not
directly initiated by the
user.
None
Version 1.4b
Parameter description
Response
Stop increasing or
decreasing the volume
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
CEC Table 24 Message Descriptions for the Audio Rate Control Feature
Opcode
value
Description
Parameters
Parameter description
Response
<Set Audio Rate>
0x9A
Used to control audio
rate from Source
Device.
[Audio Rate]
The audio rate
requested.
Perform the specified
actions, or return
a<Feature Abort>
message.
15
Directly
addressed
This message is also used in the Device Menu Control and RC Rassthrough Features
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High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 25 Message Descriptions for the Audio Return Channel Control Feature
Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
ARC Rx
device
ARC Tx
device
None
ARC Tx
device
ARC Rx
device
Used by an ARC TX
device to indicate that
its ARC functionality
has been deactivated.
None
ARC Tx
device
ARC Rx
device
0xC3
Used by an ARC TX
device to request an
ARC RX device to
activate the ARC
functionality in the ARC
TX device.
None
ARC RX device sends an
<Initiate ARC> message
ARC Rx
device
<Request ARC
Termination>
0xC4
Used by an ARC TX
device to request an
ARC RX device to
deactivate the ARC
functionality in the ARC
TX device.
None
ARC RX device sends a
<Terminate ARC>
ARC Rx
device
<Terminate ARC>
0xC5
Used by an ARC RX
device to deactivate the
ARC functionality in an
ARC TX device.
None
The ARC functionality in
the ARC TX device is
deactivated
Opcode
value
Description
Parameters
<Initiate ARC>
0xC0
Used by an ARC RX
device to activate the
ARC functionality in an
ARC TX device.
None
<Report ARC
Initiated>
0xC1
Used by an ARC TX
device to indicate that
its ARC functionality
has been activated.
<Report ARC
Terminated>
0xC2
<Request ARC
Initiation>
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Parameter description
Response
The ARC functionality in
the ARC TX device is
activated
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ARC Rx
device
Page CEC-95 of 127
ARC Tx
device
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 26 Message Descriptions for the Capability Discovery and Control Feature
Opcode
value
Description
Parameters
Parameter description
Response
<CDC Message>
0xF8
Used for Capability
Discovery and Control,
see Supplement 2
See Supplement 2
See Supplement 2
See Supplement 2
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Directly
addressed
Broadcast
Mandatory
for Initiator
Mandatory
for Follower
See
Supplement 2
See
Supplement 2
Page CEC-96 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC 16 Message Dependencies
This section describes the dependencies between each message. This section is divided into two tables, which describe the following:
CEC Table 27 describes the message dependencies when a device is capable of receiving a particular message (i.e. it does not <Feature
Abort> indicating an [“Unrecognized opcode”] in response to the message).
CEC Table 28 describes the message dependencies when a device is capable of sending a particular message.
Each table describes the additional messages that the device shall be capable of receiving and sending if a particular message is supported.
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High-Definition Multimedia Interface Specification
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CEC Table 27 Message dependencies when receiving a message
If device does not <Feature
Abort> the following message
with “Unrecognized opcode” :
It shall not <Feature Abort> the following
message(s) with “Unrecognized opcode”:
<CEC Version>
-
It shall be able to send the message(s):
<Get CEC Version>
<Clear Analogue Timer>
<Set Analogue Timer>
<Timer Cleared Status>;
<Clear Digital Timer>
<Set Digital Timer>
<Timer Cleared Status>;
<Clear External Timer>
<Set External Timer>;
<Timer Cleared Status>;
<Deck Control>
<Play>
<Deck Status>
<Deck Status>
<Device Vendor ID>
16
<Play>, <Deck Control>
<Give Device Vendor ID>
<Get CEC Version>
-
<CEC Version>
<Get Menu Language>
-
<Set Menu Language>
<Give Audio Status>
-
<Report Audio Status>
<Give Deck Status>
<Play>, <Deck Control>
<Deck Status>
<Give Device Power Status>
-
<Report Power Status>
<Give Device Vendor ID>
-
<Device Vendor ID>
<Give OSD Name>
-
<Set OSD Name>
<Give Physical Address>
-
<Report Physical Address>
<Give System Audio Mode Status>
16
<System Audio Mode Request>, <User Control
Pressed>[“Volume Up” | “Down” | “Mute”], <User Control
Released>
<Set System Audio Mode>, <System Audio
Mode Status>
This message is broadcast and there is therefore no <Feature Abort>, but devices accepting this message shall also be able to send the associated message
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High-Definition Multimedia Interface Specification
If device does not <Feature
Abort> the following message
with “Unrecognized opcode” :
Version 1.4b
It shall not <Feature Abort> the following
message(s) with “Unrecognized opcode”:
<Give Tuner Device Status>
<Image View On>
It shall be able to send the message(s):
<Tuner Device Status>
<Active Source>
17
<Inactive Source>
-
<Active Source>, <Set Stream Path>
<Initiate ARC>
<Terminate ARC>
<Report ARC Initiated>, <Report ARC Terminated>
<Menu Request>
<User Control Pressed>, <User Control Released>
<Menu Status>
<Menu Status>
-
<User Control Pressed>, <User Control Released>
<Play>
<Deck Control>
<Deck Status>
<Record Off>
<Record On>
<Record Status>
<Record On>
<Record Off>
<Record Status>
<Record Status>
<Record TV Screen>
<Record Status>
<Request Active Source> 18
<Record On>, <Record Off>
<Record On>, <Record Off>
-
<Active Source>
<Request ARC Initiation>
<Request ARC Termination>
<Initiate ARC>, <Terminate ARC>
<Request ARC Termination>
<Request ARC Initiation>
<Initiate ARC>, <Terminate ARC>
<Request Short Audio Descriptor>
<Report Short Audio Descriptor>
<Routing Change> 19
<Routing Information>
-
<Routing Information> 20
<Routing Change>
-
17
This message is broadcast and there is therefore no <Feature Abort>, but devices shall also accept the associated message.
This message is broadcast and there is therefore no <Feature Abort>, but devices accepting this message shall also be able to send the associated message.
19
This message is broadcast and there is therefore no <Feature Abort>, but devices shall also accept the associated message.
20
This message is broadcast and there is therefore no <Feature Abort>, but devices shall also accept the associated message.
18
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High-Definition Multimedia Interface Specification
If device does not <Feature
Abort> the following message
with “Unrecognized opcode” :
Version 1.4b
It shall not <Feature Abort> the following
message(s) with “Unrecognized opcode”:
It shall be able to send the message(s):
<Set Analogue Timer>
-
<Set Audio Rate>
-
<Set Digital Timer>
-
<Timer Status>
<Set External Timer>
-
<Timer Status>
<Set System Audio Mode>
<System Audio Mode Status>
<Set Menu Language>
-
<Set OSD Name>
-
<Set OSD String>
-
<Set Stream Path> 21
-
<Timer Status>
-
<System Audio Mode Request>
<User Control Pressed> [“Volume Up” | “Down” |
“Mute”], <User Control Released>
<Give OSD Name>
<Active Source> (not CEC Switches)
<System Audio Status>
<Set System Audio Mode>
<System Audio Mode Request>,
<User Control Pressed> [“Volume Up” | “Down” |
“Mute”], <User Control Released>
<System Audio Mode Request>
<Give System Audio Mode Status>,
<User Control Pressed> [“Volume Up” | “Down” |
“Mute”], <User Control Released>
<Set System Audio Mode>, <System Audio
Mode Status>
<Terminate ARC>
<Initiate ARC>
<Report ARC Initiated>, <Report ARC Terminated>
<Text View On>
<Active Source>
-
<Timer Cleared Status>
<Timer Status>
-
<Tuner Device Status>
-
<Timer Status>
-
21
<Give Tuner Device Status>
-
This message is broadcast and there is therefore no <Feature Abort>, but devices accepting this message shall also be able to send the associated message.
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High-Definition Multimedia Interface Specification
Version 1.4b
If device does not <Feature
Abort> the following message
with “Unrecognized opcode” :
It shall not <Feature Abort> the following
message(s) with “Unrecognized opcode”:
<Tuner Step Decrement>
<Tuner Step Increment>
-
<Tuner Step Increment>
<Tuner Step Decrement>
-
<User Control Pressed>
<User Control Released>
-
<User Control Released>
<User Control Pressed>
-
<Vendor Command>
<Device Vendor ID>
<Give Device Vendor ID>
<Vendor Command With ID> 22
<Device Vendor ID>
<Give Device Vendor ID>
<Vendor Remote Button Up>, <Device Vendor ID>
<Give Device Vendor ID>
<Vendor Remote Button Down>, <Device Vendor ID>
<Give Device Vendor ID>
<Vendor Remote Button Down>
<Vendor Remote Button Up>
24
23
It shall be able to send the message(s):
22
This message can be broadcast and there might not be a <Feature Abort>, but devices shall also accept the associated messages and also be able to send the
associated message.
23
This message can be broadcast and there might not be a <Feature Abort>, but devices shall also accept the associated messages and also be able to send the
associated message.
24
This message can be broadcast and there might not be a <Feature Abort>, but devices shall also accept the associated messages and also be able to send the
associated message.
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Page CEC-101 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 28 Message dependencies when sending a message
If device ever sends the
following message:
It shall be able to send the message(s):
<CEC Version>
-
It shall not <Feature Abort> the following
message(s) with “Unrecognized opcode”:
<Get CEC Version>
<Clear Analogue Timer>
<Set Analogue Timer>
<Timer Cleared Status>
<Clear Digital Timer>
<Set Digital Timer>
<Timer Cleared Status>
<Clear External Timer>
<Set External Timer>
<Timer Cleared Status>
<Deck Control>
<Play>
-
<Deck Status>
-
<Give Deck Status>, <Play>, <Deck Control>
<Device Vendor ID>
-
<Give Device Vendor ID>
<Get CEC Version>
-
<CEC Version>
<Get Menu Language>
-
<Set Menu Language> 25
<Give Deck Status>
<Play>, <Deck Control>
<Deck Status>
26
<Give Device Vendor ID>
-
<Device Vendor ID>
<Give OSD Name>
-
<Set OSD Name>
<Give Physical Address>
-
<Report Physical Address>
<Give Tuner Device Status>
-
<Tuner Device Status>
<Image View On>
<Inactive Source>
<Active Source>
27
-
<Active Source>, <Set Stream Path>
25
This message is broadcast and there is therefore no <Feature Abort>, but devices sending the associated message shall also be able to send this message.
This message is broadcast and there is therefore no <Feature Abort>, but devices sending the associated message shall also be able to send this message.
27
This message is broadcast and there is therefore no <Feature Abort>, but devices sending the associated message shall also be able to send this message.
26
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High-Definition Multimedia Interface Specification
Version 1.4b
If device ever sends the
following message:
It shall be able to send the message(s):
It shall not <Feature Abort> the following
message(s) with “Unrecognized opcode”:
<Initiate ARC>
<Terminate ARC>
<Report ARC Initiated>, <Report ARC Terminated>,
<Request ARC Initiation>,
<Request ARC Termination>
<Menu Request>
<User Control Pressed>, <User Control Released>
<Menu Status>
<Menu Status>
-
<Menu Request>, <User Control Pressed>,
<User Control Released>
<Play>
<Deck Control>
<Record Off>
<Record On>
<Record Status>
<Record On>
<Record Off>
<Record Status>
<Record Status>
<Record TV Screen>
-
<Record Status>
<Record On>, <Record Off>
<Record On>, <Record Off>
<Report Audio Status>
-
<Give Audio Status>
<Report Power Status>
-
<Give Device Power Status>
<Report Short Audio Descriptor>
<Request Active Source>
<Request Short Audio Descriptor>
-
<Active Source> 28
<Request ARC Initiation>
<Report ARC Terminated>, <Report ARC Initiated>
<Initiate ARC>, <Terminate ARC>
<Request ARC Termination>
<Report ARC Terminated>, <Report ARC Initiated>
<Initiate ARC>, <Terminate ARC>
<Routing Change>
<Routing Information> except for TV with Physical
Address 0.0.0.0
<Set Analogue Timer>
28
-
-
<Timer Status>
This message is broadcast and there is therefore no <Feature Abort>, but devices sending the associated message shall also be able to send this message.
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High-Definition Multimedia Interface Specification
If device ever sends the
following message:
Version 1.4b
It shall be able to send the message(s):
It shall not <Feature Abort> the following
message(s) with “Unrecognized opcode”:
<Set Audio Rate>
-
<Set Digital Timer>
-
<Timer Status>
<Set External Timer>
-
<Timer Status>
<Set System Audio Mode>
<System Audio Mode Status>
-
<Give System Audio Mode Status>,
<User Control Pressed> [“Volume Up” | “Down” |
“Mute”], <User Control Released>
<Set Menu Language>
-
<Get Menu Language>
<Set OSD Name>
-
<Give OSD Name>
<Set Stream Path>
-
<Active Source> (not CEC Switches)
<System Audio Mode Status>
<Set System Audio Mode>
<Give System Audio Mode Status>, <System Audio
Mode Request>, <User Control Pressed> [“Volume
Up” | “Down” | “Mute”], <User Control Released>
<System Audio Mode Request>
<User Control Pressed> [“Volume Up” | “Down” |
“Mute”], <User Control Released>
<System Audio Mode Status>, <Set System Audio
Mode>
<Terminate ARC>
<Initiate ARC>
<Report ARC Initiated>, <Report ARC Terminated>,
<Request ARC Initiation>,
<Request ARC Termination>
<Text View On>
<Active Source>
-
<Timer Cleared Status>
<Timer Status>
The relevant <Clear Analogue Timer>, <Clear Digital
Timer> or <Clear External Timer>
<Timer Status>
The relevant <Set Analogue Timer>, <Set Digital
Timer> or <Set External Timer>
<Tuner Device Status>
<Tuner Step Decrement>
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<Tuner Step Increment>
<Give Tuner Device Status>
-
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Page CEC-104 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
If device ever sends the
following message:
It shall be able to send the message(s):
<Tuner Step Increment>
<Tuner Step Decrement>
-
<User Control Released>
<User Control Pressed>
-
<Vendor Command>
<Device Vendor ID>
<Give Device Vendor ID>
<Vendor Command With ID>
<Device Vendor ID>
<Give Device Vendor ID>
<Vendor Remote Button Down>
<Vendor Remote Button Up>, <Device Vendor ID>
<Give Device Vendor ID>
<Vendor Remote Button Up>
<Vendor Remote Button Down>, <Device Vendor ID>
<Give Device Vendor ID>
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It shall not <Feature Abort> the following
message(s) with “Unrecognized opcode”:
Page CEC-105 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC 17 Operand Descriptions
In the following table, Operand Descriptions are ordered alphabetically. Sub-operands, which only occur in a single parent operand, are grouped
with their parent and are shown indented.
Not all operand values are shown in the table: these shall be considered as “reserved”.
CEC Table 29 Operand Descriptions.
Name
Range Description
[Abort Reason]
“Unrecognized opcode”
0
“Not in correct mode to respond”
1
“Cannot provide source”
2
“Invalid operand”
3
“Refused”
4
“Unable to determine”
5
“Cable”
0x00
“Satellite”
0x01
“Terrestrial”
0x02
[Analogue Broadcast Type]
Length
Purpose
1 byte
Reason for a <Feature Abort> response.
1 byte
Indicates the Analogue broadcast type
[Analogue Frequency]
0x0000<N<0xFFFF
Frequency = 62.5n kHz
2 bytes
Used to specify the frequency used by an analogue
tuner.
[ASCII digit]
0x30≤N≤0x39
1 byte
Subset of [ASCII] representing a printable digit
character.
[ASCII]
0x20≤N≤0x7E
1 byte
Represents a printable character.
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High-Definition Multimedia Interface Specification
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Name
Range Description
Length
Purpose
[Audio Format ID and Code]
[Audio Format ID]
[Audio Format Code]
1 byte
Used to indicate the audio format that TV wants to
inquire about
[Audio Format ID]
0
Bits 7-6
2 bits
Indicates that [Audio Format Code] and [Short Audio
Descriptor] are as defined in CEA-861-D.
[Audio Format Code]
If [Audio Format ID] = 0, 0x01≤N≤0x0F
Bits 5-0
6 bits
If [Audio Format ID]=0 then Audio Format Code is as
defined in CEA-861-D for CEA Short Audio
Descriptor.
“Rate Control Off”
0
1 byte
Control Off
“Standard Rate”: 100% rate
1
“Fast Rate”: Max 101% rate
2
“Slow Rate”: Min 99% rate
3
“Standard Rate”: 100.0% rate
4
“Fast Rate”: Max 100.1% rate
5
“Slow Rate”: Min 99.9% rate
6
[Audio Mute Status]
Bit 7
1 bit
[Audio Volume Status]
Bits 6-0
7 bits
“Audio Mute Off”
0
1 bit
Used to indicate the current audio mute status of a
device.
“Audio Mute On”
1
7 bits
Used to indicate the current audio volume status of a
device.
N indicates audio playback volume, expressed as a
percentage (0% - 100%). N=0 is no sound; N=100 is
maximum volume sound level.
The linearity of the sound level is device dependent.
This value is mainly used for displaying a volume
status bar on a TV screen.
[Audio Rate]
[Audio Status]
[Audio Mute Status]
[Audio Volume Status]
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Wide Range Control
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Narrow Range Control
(HDMI Transparent)
0x00≤N≤0x64
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Used to indicate the current audio status of a device.
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High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
[Boolean]
Length
0x65≤N≤0x7E
Reserved
0x7F
Current audio volume status is unknown
“False”
0
“True”
1
[Broadcast System]
0≤N≤31 – See CEC Table 31
[CEC Version]
Reserved
0x00 –
“Version 1.3a”
0x04
“Version 1.4 or Version 1.4a or Version
1.4b”
0x05
[Channel Identifier]
[Channel Number Format]
Purpose
0x03
[Channel Number Format]
[Major Channel Number]
[Minor Channel Number]
“1-part Channel Number”
0x01
“2-part Channel Number”
0x02
1 byte
Flag
1 byte
This specifies information about the color system, the
sound carrier and the IF-frequency
1 byte
Indicates the version number of the CEC Specification
which was used to design the device.
4 bytes
Identifies a 1-part Logical or Virtual Channel Number
or a
2-part Major and Minor channel combination
6 bits
Identifies Channel Format
[Major Channel Number]
If [Channel Number Format] is “2-part Channel Number”,
this operand represents a 3-digit Major channel number in
hexadecimal format;
if [Channel Number Format] is “1-part Channel Number”
this operand shall be ignored.
10 bits
Major Channel Number (if Channel Number Format is
2-part)
[Minor Channel Number]
If [Channel Number Format] is “1-part Channel Number”
this operand represents a 1-part Channel Number in
hexadecimal format;
If [Channel Number Format] is “2-part Channel Number”,
this operand represents a Minor channel number in
hexadecimal format
16 bits
1-part Channel Number, or a Minor Channel Number
(if Channel Number Format is 2-part)
1≤N≤31
1 byte
Day of month.
[Day of Month]
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High-Definition Multimedia Interface Specification
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Name
Range Description
[Deck Control Mode]
“Skip Forward / Wind”
1
“Skip Reverse / Rewind”
2
“Stop”
3
“Eject”
4
“Play”
0x11
“Record”
0x12
“Play Reverse”
0x13
“Still”
0x14
“Slow”
0x15
“Slow Reverse”
0x16
“Fast Forward”
0x17
“Fast Reverse”
0x18
“No Media”
0x19
“Stop”
0x1A
“Skip Forward / Wind”
0x1B
“Skip Reverse / Rewind”
0x1C
“Index Search Forward”
0x1D
“Index Search Reverse”
0x1E
”Other Status”
0x1F
[Deck Info]
HDMI Licensing, LLC
Length
Purpose
1 byte
Used in <Deck Control>.
Note: The “Skip Forward / Wind” and ”Skip Reverse /
Rewind” values are used for example in a DVD as
next chapter and previous chapter and in a VCR as
wind and rewind.
Confidential
1 byte
Indicates the current status of a tape or disk deck.
Page CEC-109 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
Name
Range Description
[Device Type]
“TV”
0
“Recording Device”
1
Reserved
2
“Tuner”
3
“Playback Device”
4
“Audio System”
5
“Pure CEC Switch”
6
A device according to CEC 11.1 which has no other
functionality or Device Type.
“Video Processor”
7
A device with all the following properties:
cannot itself become an Active Source;
has an HDMI output and at least one input (HDMI
or non-HDMI);
passes video from input to output modified or
unmodified;
has its own Physical Address;
requires direct addressing;
has no other device type.
[Digital Service Identification]
[Service Identification
Method]
[Service Identification Method]
[Digital Broadcast System]
[Service Identification]
“Service identified by Digital IDs”
0
“Service identified by Channel”
1
Purpose
1 byte
Used by a device to indicate its device type.
7 bytes
Indicates Digital Broadcast System and the
parameters to identify a specific service.
1 bit
Indicates that a service is identified by digital service
IDs
Indicates that a service is identified by a logical or
virtual channel number
[Digital Broadcast System]
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Length
7 bits
Confidential
Indicates the Digital Broadcast System of required
service. This is present irrespective of the state of
[Service Identification Method]
Page CEC-110 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
“ARIB generic”
0x00
“ATSC generic
0x01
“DVB generic”
0x02
“ARIB”
“ATSC”
“DVB”
[Service Identification]
[ARIB data]
29
Length
“ARIB-BS”
0x08
“ARIB-CS”
0x09
“ARIB-T”
0x0A
“Cable”
0x10
“Satellite”
0x11
“Terrestrial”
0x12
“DVB-C”
0x18
“DVB-S”
0x19
“DVB S2”
0x1A
“DVB-T”
0x1B
Generic formats
29
Specific Formats
6 bytes
[ARIB data]
Purpose
Specifies an ARIB digital service
[ATSC data]
Specifies an ATSC digital service
[DVB data]
Specifies a DVB digital service
[Channel data]
When [Service Identification Method] is “Service
identified by Channel”, this indicates the channel
number
“Transport_stream_ID”
2 bytes
The transport_stream_ID of the transport stream
carrying the required service
”Service_ID”
2 bytes
The service_ID of the required service
These formats are included for legacy devices. New devices shall use the Specific Formats starting at 0x08
HDMI Licensing, LLC
Confidential
Page CEC-111 of 127
High-Definition Multimedia Interface Specification
Name
[ATSC data]
[DVB data]
[Channel data]
[Display Control]
Version 1.4b
Range Description
Length
Purpose
”Original_Network_ID”
2 bytes
The original_network_ID of the network carrying the
transport stream for the required service
“Transport_stream_ID”
2 bytes
The transport_stream_ID of the transport stream
carrying the required service
“Program_number”
2 bytes
The Program_number of the required service
“Reserved (0x0000)”
2 bytes
Reserved
“Transport_stream_ID”
2 bytes
The transport_stream_ID of the transport stream
carrying the required service
”Service_ID”
2 bytes
The service_ID of the required service
”Original_Network_ID”
2 bytes
The original_network_ID of the network carrying the
transport stream for the required service
[Channel Identifier] [Reserved 2 bytes]}
6 bytes
Identifies the logical or virtual channel number of a
service.
See [Channel Identifier] for details.
bit 5 – bit 0 = 0
1 byte
To indicate the display mode for an on screen display
message.
Bit 7 Bit 6
HDMI Licensing, LLC
“Display for default time”
0
0
“Display until cleared”
0
1
“Clear previous message”
1
0
Reserved for future use
1
1
Confidential
Page CEC-112 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
Name
Range Description
Length
[Duration]
[Duration Hours]
[Minute]
2 bytes
0≤N≤99
1 byte
[Duration Hours]
Purpose
Duration hours in BCD format:
MS Byte
b3
b2
b1
LS Byte
b0
b3
b2
b1
b0
[External Physical Address]
[Physical Address]
2 bytes
Physical Address of device that is to be used as the
source of a recording.
See CEC 13.5.3 for information on external
connections.
[External Plug]
Plug number, 1 ≤ N ≤ 255
1 byte
External Plug number on the Recording Device.
See CEC 13.5.3 for information on external
connections.
[External Source Specifier]
“External Plug”
4
1 byte
“External Physical Address”
5
Indicates if External source is specified by the
External plug number on the Recording Device, or by
the External Physical Address of the required source
1 byte
Hour in BCD format:
[Hour]
0 ≤ N ≤ 23
MS Byte
b3
b2
b1
LS Byte
b0
b3
b2
b1
b0
[Feature Opcode]
0x00 ≤ N ≤ 0xFF (n is defined in CEC Table 8 to
CEC Table 26)
1 byte
Defines command to be performed.
[Language]
3 {[ASCII]} as defined in ISO/FDIS 639-2
[ref 1n]
3 bytes
Specify the language with which to interact with the
user.
[Menu Request Type]
“Activate”
0
1 byte
Specifies whether to activate or deactivate a devices
menu or simply query its current menu status.
“Deactivate”
1
“Query”
2
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Page CEC-113 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
Name
Range Description
[Menu State]
“Activated”
0
“Deactivated”
1
[Minute]
0≤N≤59
Length
Purpose
1 byte
Specifies the state of a device menu
1 byte
Minute in BCD format:
MS Byte
b3
b2
b1
LS Byte
b0
b3
b2
b1
b0
[Month of Year]
1≤N≤12
1 byte
Month
[New Address]
[Physical Address]
2 bytes
The Physical Address of the new device selected by a
CEC Switch.
[Original Address]
[Physical Address]
2 bytes
The Physical Address of the device de-selected by a
CEC Switch.
[OSD Name]
N {[ASCII]}, 1N 14
1 - 14 bytes
The device’s name - to be used in On Screen Display
references to it.
[OSD String]
N {[ASCII]}, 1N 13
1 - 13 bytes
A string to be displayed on the display.
[Physical Address]
4{[Port ID]}
2 bytes
Defines the path between the TV and a device – thus
giving it a Physical Address within the cluster.
0x0≤n≤0xF
4 bits
Defines one ‘hop’ within the Physical Address relating
to the physical connection of the device.
1 byte
The mode in which to play media.
[Port ID]
[Play Mode]
HDMI Licensing, LLC
“Play Forward”
0x24
“Play Reverse”
0x20
“Play Still”
0x25
“Fast Forward Min Speed”
0x05
“Fast Forward Medium Speed”
0x06
Confidential
Note: If a device does not support a particular play
mode it should select the closest match.
Page CEC-114 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
[Power Status]
“Fast Forward Max Speed”
0x07
“Fast Reverse Min Speed”
0x09
“Fast Reverse Medium Speed”
0x0A
“Fast Reverse Max Speed”
0x0B
“Slow Forward Min Speed”
0x15
“Slow Forward Medium Speed”
0x16
“Slow Forward Max Speed”
0x17
“Slow Reverse Min Speed”
0x19
“Slow Reverse Medium Speed”
0x1A
“Slow Reverse Max Speed”
0x1B
“On”
0x00
“Standby”
0x01
“In transition Standby to On”
0x02
“In transition On to Standby”
0x03
Length
Purpose
1 byte
Used to indicate the current power status of a device.
[Program Title String]
N {[ASCII]}, 1 N 14
1 - 14 bytes
Program title.
[Record Source]
{[Record Source Type]} |
{[Record Source Type] [Digital Service Identification]} |
{[Record Source Type] [Analogue Broadcast Type]
[Analogue Frequency] [Broadcast System]} |
{[Record Source Type] [External Plug]} |
{[Record Source Type] [External Physical Address]}
1 to 8 bytes (depends on
source)
To define the source for a recording.
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Page CEC-115 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
[Record Source Type]
[Record Status Info]
HDMI Licensing, LLC
Length
Purpose
1 byte
Allows the record source to be specified for a
recording.
1 byte
Indicates the status of a recording.
”Own source”
1
“Digital Service”
2
“Analogue Service”
3
“External Plug”
4
“External Physical Address”
5
“Recording currently selected source”
0x01
“Recording Digital Service”
0x02
“Recording Analogue Service”
0x03
“Recording External input”
0x04
“No recording – unable to record Digital
Service ”
0x05
No suitable tuner.
“No recording – unable to record
Analogue Service”
0x06
No suitable tuner.
“No recording – unable to select required
service”
0x07
Has suitable tuner, but the requested parameters are
invalid or out of range for that tuner.
“No recording – invalid External plug
number”
0x09
“No recording – invalid External Physical
Address”
0x0A
“No recording – CA system not supported”
0x0B
“No Recording – No or Insufficient CA
Entitlements”
0x0C
Confidential
Page CEC-116 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
Purpose
“No recording – Not allowed to copy
source”
0x0D
“No recording – No further copies
allowed”
0x0E
“No recording – no media”
0x10
“No recording – playing”
0x11
“No recording – already recording”
0x12
“No recording – media protected”
0x13
“No recording – no source signal”
0x14
“No recording – media problem”
0x15
“No recording – not enough space
available”
0x16
“No recording – Parental Lock On”
0x17
“Recording terminated normally”
0x1A
Can optionally be sent in response to a <Record Off>
message.
“Recording has already terminated”
0x1B
Can optionally be sent in response to a <Record Off>
message.
“No recording – other reason”
0x1F
[Recording Sequence]
HDMI Licensing, LLC
Length
b6……b0
“Sunday”
0b0000001
“Monday”
0b0000010
“Tuesday”
0b0000100
Confidential
Source is “copy never”.
8 bits
Indicates if recording is repeated and, if so, on which
days.
For repeated recordings, the recording sequence
value is the bitwise OR of the days when recordings
are required.
Page CEC-117 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
Length
“Wednesday”
0b0001000
“Thursday”
0b0010000
“Friday”
0b0100000
“Saturday”
0b1000000
“Once only”
0b0000000
Bit 7, reserved
0
Purpose
[Recording Sequence] shall be set to 0x00 when the
recording is not repeated.
Bit 7 is reserved and shall be set to zero.
[Reserved Bit]
0
1 bit
Used as padding bit for future extensions.
[Short Audio Descriptor]
0x000000≤N≤0xFFFFFF
3 bytes
Indicates supported audio capability. If the requested
[Audio Format ID]=0, Format of Short Audio
Descriptor is defined in CEA-861-D as CEA Short
Audio Descriptor.
[Status Request]
“On”
1
1 byte
Contains the status request mode which can be report
once or on all future state changes or reporting off.
“Off”
2
“Once”
3
2 bytes
Indicates the start time for a timer based recording.
1 byte
Specifies if the System Audio Mode is On or Off
2 bytes
Time of day
1 byte
Indicates status in a <Timer Cleared Status>
message.
[Start Time]
[Time]
[System Audio Status]
“Off”
0
“On”
1
[Time]
[Hour][Minute]
[Timer Cleared Status Data]
“Timer not cleared – recording”
0x00
“Timer not cleared – no matching”
0x01
“Timer not cleared – no info available”
0x02
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Page CEC-118 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
“Timer cleared”
[Timer Status Data]
[Timer Overlap Warning]
[Media Info]
[Timer Programmed Info]
Length
Purpose
1 byte or 3 bytes
Used by a recoding device to respond to the Initiator
of a <Set Timer> message.
1 bit
Indicates if there is another timer block already set
which overlaps with this new recording request.
2 bits
Indicates if removable media is present and its write
protect state.
5 bits or 21 bits
Gives information about how and if the programming
request has been done. [Programmed Indicator] is
used as a selector for the second parameter.
[Duration Available] can be optionally returned when:
- [Programmed Info] is “Not enough space available”
or “Might not be enough space available”; or
- [Not Programmed Info] is “Duplicate: already
programmed”
0x80
[Timer overlap warning] [Media Info]
[Timer Programmed Info]
“No overlap”
0
”Timer blocks overlap”
1
“Media present and not protected”
0b00
“Media present, but protected”
0b01
“Media not present”
0b10
Future Use
0b11
{[Programmed Indicator]}
{[Programmed Info] [Duration Available]} |
{[Not Programmed Error Info]
[Duration Available]}
Note that the length depends on whether [Duration
Available] is appended
[Programmed Indicator]
[Programmed Info]
HDMI Licensing, LLC
“Not programmed”
0
”Programmed”
1
Future Use
0b0xxx
“Enough space available for recording”
0b1000
“Not enough space available for
recording”
0b1001
Confidential
1 bit
Selector for [Timer Programmed Info].
4 bits
Information indicating any non-fatal issues with the
programming request.
Page CEC-119 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
[Not Programmed Error
Info]
HDMI Licensing, LLC
Length
Purpose
4 bits
Reason for programming failure.
“Might not be enough space available”
0b1011
“No Media info available”
0b1010
Future Use
0b0000
“No free timer available”
0b0001
“Date out of range”
0b0010
“Recording Sequence error”
0b0011
“Invalid External Plug Number”
0b0100
“Invalid External Physical Address”
0b0101
“CA system not supported”
0b0110
“No or insufficient CA Entitlements”
0b0111
No or insufficient CA entitlements
“Does not support resolution”
0b1000
Tuner does not support HD or recorder does not
support HD
“Parental Lock on”
0b1001
“Clock Failure”
0b1010
Reserved for Future Use
0b1011 to
0b1101
“Duplicate: already programmed”
0b1110
Confidential
Recording device does not support this recording
sequence, or invalid data
A timer block with identical details (of time and
service) has already been programmed
Page CEC-120 of 127
High-Definition Multimedia Interface Specification
Name
[Duration Available]
[Tuner Device Info]
[Recording Flag]
[Tuner Display Info]
Version 1.4b
Range Description
Length
Purpose
[Duration]
2 bytes
Optional parameter: Contains an estimate of the
space left on the media, expressed as a time. This
parameter may be returned when:
- [Programmed Info] is “Not enough space available”;
or
- [Not Programmed Info] is “Duplicate: already
programmed”
[Recording Flag][Tuner Display Info] {[Analogue Broadcast
Type] [Analogue Frequency][Broadcast System]} |
[Digital Service Identification]}
5 bytes (analogue service);
8 bytes (digital service)
Indicates information about the tuner. Indicates the
analogue or digital service that the tuner is set to,
regardless of whether or not it is currently displaying
the tuner. [Tuner Display Info] also indicates the data
in the following bytes.
“Not being used for recording”
0
1 bit
Indicates if the tuner is being used as a source of a
recording
“Being used for recording”
1
“Displaying Digital Tuner”
0
7 bits
“Not displaying Tuner”
1
Indicates if the device is currently displaying its tuner
or not (it may for example be displaying an external
source or media).
“Displaying Analogue tuner”
2
1 byte
Indicates type of broadcast
[UI Broadcast Type]
HDMI Licensing, LLC
“Toggle through all available broadcast
types”
0x00
“Digital / Analogue Toggle”
0x01
“Analogue”
0x10
“Analogue Terrestrial”
0x20
“Analogue Cable”
0x30
“Analogue Satellite”
0x40
“Digital”
0x50
“Digital Terrestrial”
0x60
“Digital Cable”
0x70
Confidential
Page CEC-121 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
Length
“Digital Satellite”
0x80
“Digital Communications Satellite”
0x90
“Digital Communications Satellite 2”
0x91
“IP”
0xA0
Purpose
Broadcasting Satellite in the case of a Japanese TV or
Recorder
[UI Command]
0x00≤n≤0xFF (n is defined in CEC Table 30)
1 byte
Indicates the command that the Follower is to
perform.
Note that some [UI Command] messages also have
further operands following – see CEC Table 6 and
CEC Table 7.
[UI Function Media]
Media number 1 ≤ N ≤ 255
N=0: Media number = current Media number + 1.
If current Media number = maximum number in a device,
then Media number =1.
1 byte
Number of the Media
[UI Function Select A/V input]
A/V input number 1 ≤ N ≤ 255
N=0: A/V input number = current A/V input number + 1.
If current A/V input number = maximum number in a device,
then A/V input number =1.
1 byte
Number of the A/V input
[UI Function Select Audio input]
Audio input number 1 ≤ N ≤ 255
N=0: Audio input number = current Audio input number + 1.
If current Audio input number = maximum number in a device,
then Audio input number = 1.
1 byte
Number of the Audio input
[UI Sound Presentation Control]
Indicates requested Follower operation
1 byte
Indicates the selected command.
Note: in order to toggle between available audio
languages (audio streams) associated with the current
video stream, use Sound Select,
[UI Command] = 0x33.
HDMI Licensing, LLC
"Sound Mixing Mode (Dual Mono)"
0x20
Toggle between the dual-mono mixing modes
available in the Follower (main, sub, main+sub).
"Sound Mixing Mode (Karaoke)"
0x30
Toggle between the karaoke mixing modes available
in the Follower (music only, voice only, music+voice,
cancel vocal).
"Select Audio Downmix Mode"
0x80
Toggle between the audio downmix modes available
in the Follower (e.g. mono, stereo, multi-channel).
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Page CEC-122 of 127
High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
Length
Purpose
"Select Audio Reverberation Processing"
Mode
0x90
Toggle between the available reverberation
processing (e.g. echo effects) available in the
Follower.
"Select Audio Equalizer Mode"
0xA0
Toggle between the equalizer settings available in the
Follower.
"bass step + "
0xB1
"bass neutral position"
0xB2
"bass step - "
0xB3
"treble step + "
0xC1
"treble neutral position"
0xC2
"treble step - "
0xC3
[Vendor ID]
0x000000≤N≤0xFFFFFF (n is the 24-bit unique company
ID [ref. 3i] obtained from the IEEE Registration Authority
Committee (RAC)).
3 bytes
Identifier for a specific Vendor.
[Vendor Specific Data]
Vendor specific command or data, as defined by the
manufacturer.
≤11 or ≤14 bytes (see Purpose
column)
The maximum length shall not exceed 14 Data Blocks
for <Vendor Command>; or shall not exceed 11 Data
Blocks for <Vendor Command with ID> to avoid
saturating the bus.
[Vendor Specific RC Code]
Remote Control code, as defined by the manufacturer
≤14 bytes
It is recommended to keep this as small as possible to
improve speed of response, as seen by the user.
The maximum length shall not exceed 14 Data
Blocks.
Notes: Items are transmitted in the order shown in the description.
All bit descriptions are sent most significant bit first (i.e. first bit described is sent first)
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Page CEC-123 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 30 UI Command Codes
Operation id
User Operation
Operation id
User Operation
Operation id
User Operation
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0A
0x0B
0x0C
0x0D
0x0E - 0x0F
0x10
0x11
Select
Up
Down
Left
Right
Right-Up
Right-Down
Left-Up
Left-Down
Root Menu – see Note 2
Setup Menu
Contents Menu
Favorite Menu
Exit
Reserved
Media Top Menu – See Note 3
Media Context-sensitive Menu
– see Note 4
Reserved
Number Entry Mode – See
Note 5
Number 11
Number 12
Number 0 or Number 10
Numbers 1-9
Dot
Enter
Clear
Reserved
Next Favorite
0x30
0x31
0x32
0x33
0x34
0x35
0x36
0x37
0x38
0x39 - 0x3F
0x40
0x41
0x42
0x43
0x44
0x45
0x46
Channel Up
Channel Down
Previous Channel
Sound Select
Input Select
Display Information
Help
Page Up
Page Down
Reserved
Power
Volume Up
Volume Down
Mute
Play
Stop
Pause
0x52
0x53
0x54
0x55
0x56
0x57
0x58 – 0x5F
0x60
0x61
0x62
0x63
0x64
0x65
0x66
0x67
0x68
0x69
Video on Demand
Electronic Program Guide
Timer Programming
Initial Configuration
Select Broadcast Type
Select Sound Presentation
Reserved
Play Function
Pause-Play Function
Record Function
Pause-Record Function
Stop Function
Mute Function
Restore Volume Function
Tune Function
Select Media Function
Select A/V Input Function
0x47
0x48
Record
Rewind
0x6A
0x6B
Select Audio Input Function
Power Toggle Function
0x49
0x4A
0x4B
0x4C
0x4D
0x4E
0x4F
0x50
0x51
Fast forward
Eject
Forward
Backward
Stop-Record
Pause-Record
Reserved
Angle
Sub picture
0x6C
0x6D
0x6E – 0x70
0x71
0x72
0x73
0x74
0x75
0x76
0x77 – 0xFF
Power Off Function
Power On Function
Reserved
F1 (Blue)
F2 (Red)
F3 (Green)
F4 (Yellow)
F5
Data – see Note 6
Reserved
0x12 – 0x1C
0x1D
0x1E
0x1F
0x20
0x21 - 0x29
0x2A
0x2B
0x2C
0x2D - 0x2E
0x2F
For notes, see following page.
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Page CEC-124 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
Note 1: The elements identified in bold are the only ones which are forwarded as part of the device Menu Control feature, see section CEC 13.12.
Note 2: This triggers the initial display that a device shows. It is device-dependent and can be, for example, a contents menu, setup menu, favorite
menu or other menu. The actual menu displayed may also depend on the device’s current state.
Note 3: This triggers the display of the main menu available for the currently playing media, e.g. DVD/BD Top Menu to select Language, Subtitle,
Scene, Bonus, Start of Film, etc.
Note 4: This triggers the display of a context-sensitive media-related menu (e.g. DVD Menu or BD Popup Menu), typically containing functions to
adapt the playback of the currently playing content.
Note 5: Selects an available Number Entry Mode that may be implemented on a device, such as: 1-12-key entry mode, 0-9-key entry mode, single
or multiple digit entry.
Note 6: This is used, for example, to enter or leave a digital TV data broadcast application.
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Page CEC-125 of 127
High-Definition Multimedia Interface Specification
Version 1.4b
CEC Table 31 Broadcast System
System
Value
Bits
43210
Sound
Carrier
Sound
Modulation
Video
Modulation
Vertical
Frequency
Color subcarrier
PAL B/G
0
00000
5.5 MHz
FM
neg
50 Hz
4.43 MHz
SECAM L’
1
00001
6.5 MHz
AM
Pos
50 Hz
30
PAL M
2
00010
4.5 MHz
FM
neg
60 Hz
3.5756MHz
NTSC M
3
00011
4.5 MHz
FM
neg
60 Hz
3.5795MHz
PAL I
4
00100
6.0 MHz
FM
neg
50 Hz
4.43 MHz
SECAM DK
5
00101
6.5 MHz
FM
neg
50 Hz
30
SECAM B/G
6
00110
5.5 MHz
FM
neg
50 Hz
30
SECAM L
7
00111
6.5 MHz
AM
pos
50 Hz
30
PAL DK
8
01000
6.5 MHz
FM
neg
50 Hz
4.43 MHz
Future use
9
01001
..
..
..
Future use
30
11110
31
11111
Other System
31
30
31
Color sub-carriers SECAM: fOB 4.25 MHz, fOR 4.406 MHz
The system is not defined. The receiving device decides locally what to do.
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High-Definition Multimedia Interface Specification
CEC Appendix A
Version 1.4b
Non-CEC Switch (Informative)
There are two types of non-CEC Switches, those which have only one EDID for all source devices (or simply
reflect the sink EDID), and those which have a separate EDID for all source devices. The rules for the
operation of these two types of Switch are different:
Note that the use of non-CEC Switches is deprecated, see CEC 11.
CEC A1
Switches with One EDID
A non-CEC-compliant Switch may have a single child_address, which is always occupied by the currently
switched device. Any other connected devices will have no hot plug signal and will therefore have an
unallocated Physical Address (and can use only the unregistered Logical Address). These devices will,
however, still see CEC messages as they will be connected to the CEC line and they may react to some
broadcast messages in the normal way (e.g. <Standby>).
When a Switch de-selects a device, that device will detect the removal of the ‘hot plug’ signal to indicate that
its physical AV connection has been removed. It should immediately clear its physical and Logical Addresses.
Each source device below the Switch will detect the removal of the ‘hot plug’ signal to indicate they are no
longer on the active AV Path and clear their addresses accordingly.
When a Switch selects a device, that device will detect the ‘hot plug’ signal. It can then obtain a valid Physical
Address from its sink and subsequently a Logical Address. The device should activate the hot plug signal to
its source (child) devices (if any) to indicate that they should now request a Physical Address.
Non CEC Switch deselects device ("Hot Plug" signal removed) /
clear physical and logical address
HDMI connection unplugged ("Hot Plug" signal removed) /
clear physical and logical address
Connected
Unconnected
HDMI connection plugged in ("Hot Plug" signal detected) /
query sink for physical address
Non CEC Switch selects device ("Hot Plug" signal detected) /
query sink for physical address
CEC Figure A1 A device’s behavior when it is beneath a 1 EDID non-CEC Switch.
CEC A2
Switches with Multiple EDIDs
These should operate as CEC Switches except that they do not send messages on, or monitor, the CEC line.
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High-Definition Multimedia Interface Specification
Version 1.4b
Supplement 2
HDMI Ethernet and Audio Return Channel (HEAC)
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High-Definition Multimedia Interface Specification
Version 1.4b
Table of Contents
HEAC 1
Introduction....................................................................................................................................... 1
HEAC 1.1
Normative References .............................................................................................................. 1
HEAC 1.2
Informative References ............................................................................................................. 1
HEAC 1.3
Glossary of terms ...................................................................................................................... 2
HEAC 1.4
Acronyms and Abbreviations .................................................................................................... 2
HEAC 1.5
Document Revision History....................................................................................................... 3
HEAC 2
Physical Layer .................................................................................................................................. 4
HEAC 2.1
Connectors ................................................................................................................................ 4
HEAC 2.1.1
Overview of Connectors for HEAC........................................................................................ 4
HEAC 2.1.2
Connector Pin Assignments for HEAC.................................................................................. 4
HEAC 2.1.3
Cable Adapter Specification for HEAC.................................................................................. 7
HEAC 2.1.3.1
Type A Plug to Type A Plug for HEAC ................................................................................. 8
HEAC 2.1.3.2
Type C Plug to Type C Plug for HEAC................................................................................. 9
HEAC 2.1.3.3
Type C Plug to Type A Plug for HEAC ............................................................................... 10
HEAC 2.1.3.4
Type D Plug to Type A Plug for HEAC ............................................................................... 11
HEAC 2.2
HEAC 2.2.1
Electrical Specification ............................................................................................................ 12
Overview.............................................................................................................................. 12
HEAC 2.3
System Operating Conditions ................................................................................................. 14
HEAC 2.4
Transmission Conditions......................................................................................................... 15
HEAC 2.5
Differential Signal Characteristics ........................................................................................... 15
HEAC 2.6
Common Mode Signal Characteristics.................................................................................... 17
HEAC 2.7
Single Mode Signal Characteristics ........................................................................................ 20
HEAC 2.8
Receiver Performance ............................................................................................................ 22
HEAC 2.9
Cable Assembly Characteristics ............................................................................................. 23
HEAC 3
Capability Discovery and Control ................................................................................................... 26
HEAC 3.1
Protocol General Rules ........................................................................................................... 26
HEAC 3.1.1
Maximum Response Time................................................................................................... 27
HEAC 3.1.2
Error Code ........................................................................................................................... 27
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HEAC 3.1.3
HEAC 3.2
Version 1.4b
Physical HPD pin................................................................................................................. 27
Feature Description................................................................................................................. 28
HEAC 3.2.1
HDMI Ethernet Channel ...................................................................................................... 28
HEAC 3.2.1.1
Messages............................................................................................................................ 28
HEAC 3.2.1.2
Channels, Channel States and State Transitions............................................................... 28
HEAC 3.2.1.3
HEC Capability Discovery................................................................................................... 30
HEAC 3.2.1.4
HEC Control........................................................................................................................ 33
HEAC 3.2.1.5
HEC Control for Adjacent Devices ..................................................................................... 40
HEAC 3.2.1.6
Best Practices ..................................................................................................................... 41
HEAC 3.2.2
CDC_HPD (CDC Hot Plug Detect signal) ........................................................................... 42
HEAC 3.2.2.1
Messages............................................................................................................................ 42
HEAC 3.2.2.2
Feature Description ............................................................................................................ 42
HEAC 3.2.2.3
Additional Source Requirements ........................................................................................ 44
HEAC 3.3
Message Descriptions............................................................................................................. 47
HEAC 3.4
Message Dependencies.......................................................................................................... 53
HEAC 3.5
Operand Descriptions ............................................................................................................. 55
HEAC 4
Audio Return Channel .................................................................................................................... 59
HEAC 4.1
Overview ................................................................................................................................. 59
HEAC 4.2
Relationship with IEC 60958/IEC 61937................................................................................. 59
HEAC 4.3
Functionality ............................................................................................................................ 59
HEAC 5
Networking...................................................................................................................................... 61
HEAC 5.1
Relationship Between HEC and 100Base-TX......................................................................... 61
HEAC 5.2
Layer Architecture ................................................................................................................... 61
HEAC 5.3
Network Topology ................................................................................................................... 62
HEAC 5.4
HEC Device Types.................................................................................................................. 62
HEAC 5.5
Ethernet Switching Functionality ............................................................................................. 63
HEAC 5.6
Connection to Internet via Home Network .............................................................................. 65
HEAC 5.7
Loop Detection and Loop Removal......................................................................................... 65
HEAC 5.7.1
HEAC 5.8
Loop Detection Requirements ............................................................................................. 66
QoS ......................................................................................................................................... 67
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High-Definition Multimedia Interface Specification
HEAC 6
Version 1.4b
Appendices..................................................................................................................................... 69
HEAC Appendix A
MAC Frame Format (Informative) ............................................................................... 69
HEAC Appendix B
User Priority with Respect to Traffic Class Mapping (Informative).............................. 70
HEAC Appendix C
User Priority with Respect to Traffic Type Mapping.................................................... 71
HEAC Appendix D
Connection to the Home Network and Internet........................................................... 72
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Version 1.4b
Figures
HEAC Figure 2-1 Transmission Waveform................................................................................................... 12
HEAC Figure 2-2 Illustration of Fundamental Structure (Differential mode and Common mode) ......... 13
HEAC Figure 2-3 Illustration of ARC-only receiver (Single Mode/Common Mode) and Single Mode
ARC-only transmitter ..................................................................................................................................... 14
HEAC Figure 2-4 Illustration of the HEAC Differential Signal.................................................................. 16
HEAC Figure 2-5 Differential Signal Test Point .......................................................................................... 17
HEAC Figure 2-6 HEAC Common Mode Signal on each HEAC+/- Line .................................................... 18
HEAC Figure 2-7 Common Mode Signal Test Point .................................................................................... 20
HEAC Figure 2-8 ARC Single Mode Signal on HEAC+ ............................................................................... 21
HEAC Figure 2-9 Single Mode Signal Test Point......................................................................................... 22
HEAC Figure 2-10 Simultaneous Transmission Waveform ........................................................................ 23
HEAC Figure 2-11 HEAC Signal-Line Differential Insertion Loss............................................................. 25
HEAC Figure 3-1 CDC message frame ......................................................................................................... 27
HEAC Figure 3-2 HEC Channel State Transition Diagram........................................................................ 30
HEAC Figure 3-3 Devices with different HEC Capabilities ........................................................................ 31
HEAC Figure 3-4 Network example incorporating devices with different HEC Capabilities................... 32
HEAC Figure 3-5 Discovery of all HEC capable devices and their Capabilities ........................................ 33
HEAC Figure 3-6 Capability Notification ..................................................................................................... 33
HEAC Figure 3-7 HEC capability and state inquiry.................................................................................... 34
HEAC Figure 3-8 Example for an HDMI network ....................................................................................... 36
HEAC Figure 3-9 Activation of an HDMI Ethernet Channel (HEC) .......................................................... 36
HEAC Figure 3-10 HDMI network example for multiple VHEC activation............................................... 37
HEAC Figure 3-11 Activation of multiple HDMI Ethernet Channel (HEC) .............................................. 37
HEAC Figure 3-12 Deactivation of an AHEC by its Activator .................................................................... 38
HEAC Figure 3-13 Request deactivation of an AHEC by a device part of that AHEC.............................. 38
HEAC Figure 3-14 AHEC safety mechanism ............................................................................................... 39
HEAC Figure 3-15 Disable and Enable of reading EDID and restarting CP (1)........................................ 42
HEAC Figure 3-16 Disable and Enable of reading EDID and restarting CP (2)........................................ 44
HEAC Figure 3-17 A timing example of CDC_HPD messages and CP&EDID_HPD................................ 45
HEAC Figure 3-18 A timing example of CDC_HPD messages and EDID_HPD........................................ 46
HEAC Figure 4-1 Audio Return Channel Overview..................................................................................... 59
HEAC Figure 5-1 Layer Architecture............................................................................................................ 61
HEAC Figure 5-2 Example of an HEC Network........................................................................................... 62
HEAC Figure 5-3 HEC Device Types ............................................................................................................ 63
HEAC Figure 5-4 Example of a Connection to the Internet ........................................................................ 65
HEAC Figure 5-5 Example of a Network Loop ............................................................................................. 66
HEAC Figure 5-6 Example of Three Device Cases with Respect to Conditions for Loop Detection and
Removal Capability......................................................................................................................................... 67
HEAC Figure 6-1 MAC Frame Format ......................................................................................................... 69
HEAC Figure 6-2 An Example of DLNA User Priority for Traffic Class Mapping .................................... 70
HEAC Figure 6-3 Examples of Connection to the Home Network and Internet........................................ 72
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High-Definition Multimedia Interface Specification
Version 1.4b
Tables
HEAC Table 2-1 Type A Connector Pin Assignment...................................................................................... 4
HEAC Table 2-2 Type C Connector Pin Assignment...................................................................................... 5
HEAC Table 2-3 Type D Connector Pin Assignment ..................................................................................... 6
HEAC Table 2-4 Wire Categories .................................................................................................................... 7
HEAC Table 2-5 Type A-to-Type A Cable Wire Assignment ......................................................................... 8
HEAC Table 2-6 Type C-to-Type C Cable Wire Assignment ......................................................................... 9
HEAC Table 2-7 Type C-to-Type A Cable Wire Assignment ....................................................................... 10
HEAC Table 2-8 Type D-to-Type A Cable Wire Assignment ....................................................................... 11
HEAC Table 2-9 HEAC Operating Conditions ............................................................................................. 14
HEAC Table 2-10 Required Transmission Conditions ................................................................................. 15
HEAC Table 2-11 Differential Transmission Characteristics at TP1 and TP2 .......................................... 16
HEAC Table 2-12 HEAC Common Mode Transmission Characteristics at TP2........................................ 18
HEAC Table 2-13 HEAC Common Mode Transmission Characteristics at TP1........................................ 19
HEAC Table 2-14 HEAC Single Mode Transmission Characteristics at TP2 ............................................ 21
HEAC Table 2-15 HEAC Single Mode Transmission Characteristics at TP1 ............................................ 21
HEAC Table 2-16 HEAC Impedance Characteristics................................................................................... 23
HEAC Table 2-17 HEAC+/- Lines Cable Assembly ...................................................................................... 24
HEAC Table 3-1 Possible HECs within a certain HDMI network .............................................................. 29
HEAC Table 3-2 HEC Channel States .......................................................................................................... 29
HEAC Table 3-3 HEC Capability Definition................................................................................................. 31
HEAC Table 3-4 Message Descriptions for the HDMI Ethernet Channel Feature ................................... 48
HEAC Table 3-5 Message Descriptions for the CDC_HPD Feature ........................................................... 51
HEAC Table 3-6 Message Dependencies when receiving a CDC message ................................................. 53
HEAC Table 3-7 Message Dependencies when sending a CDC message ................................................... 53
HEAC Table 3-8 Operand descriptions for CDC messages.......................................................................... 55
HEAC Table 6-1 HEC Mapping for User Priority Traffic Type................................................................... 71
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HEAC 1
Version 1.4b
Introduction
HDMI Ethernet and Audio Return Channel (HEAC) enhances the HDMI standard through the addition of a
high-speed bidirectional data communication link which is derived from the 100Base-TX IEEE 802.3 standard
[4n] and audio data streaming which leverages the IEC60958-1 standard [1n].
HEAC provides a full duplex connection between HDMI devices which conforms to the 100Base-TX IEEE
802.3 standard. HEAC defines a Category 1 and 2 HDMI cable which is able to carry the high-speed data
signals. This transmission is defined as the HDMI Ethernet Channel (HEC).
Furthermore, HEAC provides audio data streaming which conforms to the IEC 60958-1 standard from an
HDMI Sink to an HDMI Source or Repeater. This transmission is defined as the Audio Return Channel (ARC).
HEAC 1.1
Normative References
[1n] IEC, IEC 60958-1, “Digital audio interface – Part 1: General”, Third edition 2008-09
[2n] IEC, IEC 61937-1, “Digital Audio - Interface for non-linear PCM encoded audio bitstreams applying IEC
60958 - Part 1: General”, Second edition 2007-01
[3n] IEC, IEC 61937-2, “Digital Audio - Interface for non-linear PCM encoded audio bitstreams applying IEC
60958 - Part 2: Burst-Info”, Second edition 2007-05
[4n] IEEE 802.3-2005, IEEE Standard for information technology - Telecommunications and information
exchange between systems - Local and metropolitan area networks - Specific requirements - Part 3: Carrier
sense multiple access with collision detection (CSMA/CD) access method and physical layer specification
[5n] IEEE 802.1D-2004, IEEE Standard for Information technology - Telecommunications and information
exchange between systems - IEEE standard for local and metropolitan area networks - Common
specifications - Media access control (MAC) Bridges
[6n] IEEE 802.1Q-2003, IEEE Standard for Information Technology - Telecommunications and information
exchange between systems - IEEE standard for local and metropolitan area networks - Common
specifications - Virtual Bridged Local Area Networks
HEAC 1.2
Informative References
[1i] DLNA Networked Device Interoperability Guidelines expanded: March 2006, Volume 1: Architectures and
Protocols
[2i] IEC, IEC7498-1, "Information technology - Open Systems Interconnection - Basic Reference Model: The
Basic Model", Second edition 1994-11
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High-Definition Multimedia Interface Specification
HEAC 1.3
Version 1.4b
Glossary of terms
Activator(s)
An Activator is a device which has successfully activated an HDMI Ethernet
Channel. Note that a device acting only as an Activator is neither required to
support the HEAC physical layer nor any of the HEAC features but it shall
be fully compliant to HEAC CDC.
External Network
An External Network is a communication network connecting devices
(usually IP based) without the usage of an HDMI Ethernet Channel. Devices
supporting HEC might provide the possibility to connect to an External
Network using an External Network Connection.
External Network Connection
Refer to HEAC Table 3-3 for a detailed definition.
HEC Functionality
Refer to HEAC Table 3-3 for a detailed definition.
Host Functionality
Refer to HEAC Table 3-3 for a detailed definition.
Layer 2 switch (L2 SW)
A device consisting of a single port or multiple ports and control logic. It
includes Ethernet switching functionality on layer 2. Refer to [5n]
Maximum Response Time
The maximum time to respond to received messages (see HEAC 3.1.1).
MLT-3
The MLT-3 (multi-level signal) encoder receives the scrambled
Non-Return to Zero (NRZ) data stream from the scrambler and encodes
the stream. The output of the MLT-3 encoder has three levels. The 125
Mbps bit stream from the MLT-3 encoder is driven onto a cable by drivers.
Refer to [4n]
Open System
Interconnection (OSI) 7-layer
reference model
The OSI Reference Model defines a seven-layer model for data
communication with the physical transport at the lower layer and
application protocols at the upper layers. Refer to [2i]
Terminating Device(s)
The Terminating Devices are the two devices at both ends of an HDMI
Ethernet Channel. An HDMI Ethernet Channel can be fully identified by its
Terminating Devices. See also HEAC 3.2.1.2.
HEAC 1.4
Acronyms and Abbreviations
AHEC
Active HDMI Ethernet Channel
ARC
Audio Return Channel
BPDU
Bridge Protocol Data Unit ( Refer to [5n] )
CDC
Capability Discovery and Control
CEC
Consumer Electronics Control
CP
Content Protection
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High-Definition Multimedia Interface Specification
HEAC
HDMI Ethernet and Audio Return Channel
HEC
HDMI Ethernet Channel
MRT
Maximum Response Time
PA
Physical Address
PHEC
Potential HDMI Ethernet Channel
VHEC
Verified HDMI Ethernet Channel
HEAC 1.5
Version 1.4b
Document Revision History
1.4b
2011/10/11
No changes
1.4a
2010/02/25
Clarified Parameter descriptions of <CDC_HPD_SetState> and
<CDC_HPD_ReportState> (HEAC Table 3-5)
1.4
2009/06/05
Initial Release
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High-Definition Multimedia Interface Specification
HEAC 2
Version 1.4b
Physical Layer
The following sections describe the fundamental architecture and requirements for the electrical and cable
characteristics of HEAC.
Within Supplement 2, HEAC- denotes HPD/HEAC- and HEAC+ denotes Utility/HEAC+ respectively.
HEAC 2.1
Connectors
HEAC 2.1.1
Overview of Connectors for HEAC
HEAC utilizes the Utility and HPD lines for signal transmission. The pin assignments for Type A, Type C and
Type D connectors and the cable adapters are defined in the following sections.
HEAC 2.1.2
Connector Pin Assignments for HEAC
HEAC Table 2-1 Type A Connector Pin Assignment
PIN
Signal Assignment
PIN
Signal Assignment
1
TMDS Data2+
2
TMDS Data2 Shield
3
TMDS Data2–
4
TMDS Data1+
5
TMDS Data1 Shield
6
TMDS Data1–
7
TMDS Data0+
8
TMDS Data0 Shield
9
TMDS Data0–
10
TMDS Clock+
11
TMDS Clock Shield
12
TMDS Clock–
13
CEC
14
Utility / HEAC+
15
SCL
16
SDA
17
DDC/CEC Ground / HEAC
Shield
18
+5V Power
19
Hot Plug Detect / HEAC-
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High-Definition Multimedia Interface Specification
Version 1.4b
HEAC Table 2-2 Type C Connector Pin Assignment
PIN
Signal Assignment
1
TMDS Data2 Shield
2
TMDS Data2+
3
TMDS Data2-
4
TMDS Data1 Shield
5
TMDS Data1+
6
TMDS Data1-
7
TMDS Data0 Shield
8
TMDS Data0+
9
TMDS Data0-
10
TMDS Clock Shield
11
TMDS Clock+
12
TMDS Clock-
13
DDC/CEC Ground / HEAC
Shield
14
CEC
15
SCL
16
SDA
17
Utility / HEAC+
18
+5V Power
19
Hot Plug Detect / HEAC-
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Version 1.4b
HEAC Table 2-3 Type D Connector Pin Assignment
PIN
Signal Assignment
PIN
Signal Assignment
1
Hot Plug Detect / HEAC-
2
Utility / HEAC+
3
TMDS Data2+
4
TMDS Data2 Shield
5
TMDS Data2–
6
TMDS Data1+
7
TMDS Data1 Shield
8
TMDS Data1–
9
TMDS Data0+
10
TMDS Data0 Shield
11
TMDS Data0–
12
TMDS Clock+
13
TMDS Clock Shield
14
TMDS Clock–
15
CEC
16
DDC/CEC Ground / HEAC
Shield
17
SCL
18
SDA
19
+5V Power
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High-Definition Multimedia Interface Specification
HEAC 2.1.3
Version 1.4b
Cable Adapter Specification for HEAC
HEAC Table 2-4 Wire Categories
Category
A
B
C
D
E
F
N.C.
5V
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TMDS Signal Wire
TMDS Shield
Control
Control Ground
HEAC Signal Wire
HEAC Shield
No connect (no wire)
5 Volts Power Wire
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High-Definition Multimedia Interface Specification
Version 1.4b
Type A Plug to Type A Plug for HEAC
HEAC 2.1.3.1
HEAC Table 2-5 Type A-to-Type A Cable Wire Assignment
Type A pin
Signal Name
Wire
(HEAC)
Type A pin
1
TMDS Data2+
A
1
2
TMDS Data2 Shield
B
2
3
TMDS Data2–
A
3
4
TMDS Data1+
A
4
5
TMDS Data1 Shield
B
5
6
TMDS Data1–
A
6
7
TMDS Data0+
A
7
8
TMDS Data0 Shield
B
8
9
TMDS Data0–
A
9
10
TMDS Clock+
A
10
11
TMDS Clock Shield
B
11
12
TMDS Clock–
A
12
13
CEC
C
13
14
Utility / HEAC+
E
14
15
SCL
C
15
16
SDA
C
16
17
DDC/CEC Ground / HEAC Shield
F
17
18
+5V Power
5V
18
19
Hot Plug Detect / HEAC-
E
19
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High-Definition Multimedia Interface Specification
Version 1.4b
Type C Plug to Type C Plug for HEAC
HEAC 2.1.3.2
HEAC Table 2-6 Type C-to-Type C Cable Wire Assignment
Type C pin
Signal Name
Wire
(HEAC)
Type C pin
1
TMDS Data2 Shield
B
1
2
TMDS Data2+
A
2
3
TMDS Data2-
A
3
4
TMDS Data1 Shield
B
4
5
TMDS Data1+
A
5
6
TMDS Data1-
A
6
7
TMDS Data0 Shield
B
7
8
TMDS Data0+
A
8
9
TMDS Data0-
A
9
10
TMDS Clock Shield
B
10
11
TMDS Clock+
A
11
12
TMDS Clock-
A
12
13
DDC/CEC Ground / HEAC Shield
F
13
14
CEC
C
14
15
SCL
C
15
16
SDA
C
16
17
Utility / HEAC+
E
17
18
+5V Power
5V
18
19
Hot Plug Detect / HEAC-
E
19
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High-Definition Multimedia Interface Specification
Version 1.4b
Type C Plug to Type A Plug for HEAC
HEAC 2.1.3.3
HEAC Table 2-7 Type C-to-Type A Cable Wire Assignment
Type C pin
Signal Name
Wire
(HEAC)
Type A pin
1
TMDS Data2 Shield
B
2
2
TMDS Data2+
A
1
3
TMDS Data2-
A
3
4
TMDS Data1 Shield
B
5
5
TMDS Data1+
A
4
6
TMDS Data1-
A
6
7
TMDS Data0 Shield
B
8
8
TMDS Data0+
A
7
9
TMDS Data0-
A
9
10
TMDS Clock Shield
B
11
11
TMDS Clock+
A
10
12
TMDS Clock-
A
12
13
DDC/CEC Ground / HEAC Shield
F
17
14
CEC
C
13
15
SCL
C
15
16
SDA
C
16
17
Utility / HEAC+
E
14
18
+5V Power
5V
18
19
Hot Plug Detect / HEAC-
E
19
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High-Definition Multimedia Interface Specification
Version 1.4b
Type D Plug to Type A Plug for HEAC
HEAC 2.1.3.4
HEAC Table 2-8 Type D-to-Type A Cable Wire Assignment
Type D pin
Signal Name
Wire
(HEAC)
Type A pin
E
19
1
Hot Plug Detect / HEAC-
2
Utility / HEAC+
E
14
3
TMDS Data2+
A
1
4
TMDS Data2 Shield
B
2
5
TMDS Data2-
A
3
6
TMDS Data1+
A
4
7
TMDS Data1 Shield
B
5
8
TMDS Data1-
A
6
9
TMDS Data0+
A
7
10
TMDS Data0 Shield
B
8
11
TMDS Data0-
A
9
12
TMDS Clock+
A
10
13
TMDS Clock Shield
B
11
14
TMDS Clock-
A
12
15
CEC
C
13
16
DDC/CEC Ground / HEAC Shield
F
17
17
SCL
C
15
18
SDA
C
16
19
+5V Power
5V
18
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HEAC 2.2
Electrical Specification
HEAC 2.2.1
Overview
For HDMI Ethernet and Audio Return Channel (HEAC), the signal pair composed of the HEAC- and the
HEAC+ lines or only the HEAC+ line is used for transmission.
The HEAC transmission is composed of HEC transmission and ARC transmission. HEC transmission employs
MLT-3 signaling in differential mode. ARC transmission employs a single IEC 60958-1 signal in common
mode or single mode. Each combination (HEC transmission only, ARC transmission only or HEC transmission
with ARC transmission in common mode) is allowed.
For HEC transmission, Source and Sink exchange 100BASE-TX data through a differential pair with a 125
MSymbol/s (+/-50ppm) MLT-3 signal, which is simultaneously bidirectional (full-duplex). The signals are
transmitted with attenuated amplitude compared to the normal 100BASE-TX Ethernet signal, and are
transmitted on a set of biased lines. A single pair of wires is used to transmit in both directions simultaneously.
For ARC transmission, the HDMI Sink transmits a single IEC 60958-1 stream as a common mode component
on the HEAC+/- differential pair with or without MLT-3 signals, or only the HEAC+ line is used for single mode
transmission without MLT-3 signals, to an HDMI Source in the reverse direction from the TMDS signals.
When transmitting ARC in common mode, although it is possible to simultaneously transmit with MLT-3, it is
not necessary to synchronize with that signal. In single mode ARC transmission it is not possible to transmit
simultaneously with MLT-3. When simultaneously transmitting with MLT-3, transmission shall be performed in
common mode. An HDMI Sink that supports ARC shall support either common mode or single mode
transmission. An HDMI Source that supports ARC shall be capable to receive both common mode as well as
single mode transmission. In HEAC Figure 2-1, examples of the HEC (differential mode) and ARC (common
mode) simultaneous transmission waveforms are shown.
4.4V
4.3V
4.2V
4.1V
4.0V
3.9V
3.8V
3.7V
3.6V
HEAC+
HEAC-
Common Mode Signal Common Mode Signal
=High
=Low
HEAC Figure 2-1 Transmission Waveform
The HEAC signal is transmitted in compliance with the HPD characteristics defined in section 4.2.9 of the main
specification.
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The HEC signal is the sum of the Tx and Rx MLT-3 signals onto a single pair with attenuated amplitude
compared to 100BASE-TX Ethernet MLT-3 transmission.
HEAC Figure 2-2 shows HEAC's fundamental structure where HEC and ARC in common mode are both
applied.
HEAC Figure 2-2 Illustration of Fundamental Structure (differential mode and common mode)
The differential lines shall be terminated by a resistor via AC coupling in both the Source and Sink. This
Termination resistor and AC coupling is matched to the characteristic impedance of the cable with sufficient
bandwidth to exchange MLT-3 signals between the devices.
Full duplex bi-directional communication is performed by the HEAC transmitters in both Source and Sink. The
transceiver consists of a high-impedance current driver that supplies current in proportion to the MLT-3 signal
and IEC 60958-1 signal from the HDMI Sink side to the line pair and termination resistance in the connected
device. A differential voltage sensor with a high impedance input is used in both Source and Sink to observe
the differential voltage across the termination resistance, Redt.
When a Source and Sink are connected with a cable and the MLT-3 transmission is active, the differential
voltage across the termination resistance, Redt, in one device is the sum of the driving MLT-3 signal of that
device and the MLT-3 signal from the other device. The device is able to detect with its sensor the incoming
MLT-3 signal by subtracting the detected differential signal from its current driver's outgoing MLT-3 signal. In
addition, when the HDMI Sink is simultaneously transmitting ARC in common mode, the HDMI Source is
capable of detecting with its sensor the IEC 60958-1 signal by summing the HEAC+ and HEAC- signals, to
retrieve the common mode signal.
The differential impedance between the HEAC+/- lines and the DC bias of the HEAC+/- differential line
provided by the Sink shall meet the specification in section HEAC 2.8. The Sink shall meet the DC bias
specifications in section HEAC 2.3.
The HEAC+/- differential line in the cable shall meet the specifications for the characteristic impedance and
insertion loss in section HEAC 2.9.
HEAC Figure 2-3 shows HEAC's fundamental structure where ARC in single mode is applied.
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HDMI Source Device
Version 1.4b
HDMI Sink Device
HEACHEAC+
Rest
Rest
IEC 60958 TX
IEC 60958 RX
Rest
HEAC Figure 2-3 Illustration of ARC-only receiver (Single Mode/Common Mode) and Single Mode ARC-only transmitter
The single line shall be terminated by a resistor via AC coupling in both the Source and Sink. This Termination
resistor is matched to the characteristic impedance of the cable with sufficient bandwidth to exchange the IEC
60958-1 signal.
The single mode impedance of the Sink shall meet the specification. The Sink shall meet the DC bias
specifications.
HEAC 2.3
System Operating Conditions
The following HEAC Table 2-9 shows HEAC operating conditions:
HEAC Table 2-9 HEAC Operating Conditions
Item
Value
Operating DC voltage (HPD High condition), Veh
differential and/or common mode transmission
4.0 Volts 10%
when +5V Power is high
Operating DC voltage , Vel
Single mode only Transmission
0 ≦Vel ≦5.0 Volts
Termination differential resistance, Redt
100 ohms 10%
Termination common mode resistance, Rect
30 ohms 20%
Termination single mode resistance, Rest
55 ohms 35%
The Operating DC Voltage may be derived from the +5V Power.
Redt is specified for HEC MLT-3 transmission. Rect is specified for ARC IEC 60958 transmission in common
mode. Rest is specified for ARC IEC 60958 transmission in single mode.
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Transmission Conditions
It is possible to start HEC transmission once the conditions as described in section HEAC 3 Capability
Discovery and Control are met, the following conditions for the bias voltage are met, and +5V Power is
asserted high. If these conditions are not met, HEC transmission shall not be used.
It is possible to start ARC transmission once the conditions as described in CEC Section 13.17 Audio Return
Channel Control are met, the following conditions for the bias voltage are met, and +5V Power is asserted
high. If these conditions are not met, ARC transmission shall not be used.
The High and Low voltage levels of the HEAC+/- lines used in this section are defined in Section 4.2.9, Hot
Plug Detect Signal. When both HEAC+/- lines are biased to a High level and the other conditions mentioned
above are met, an MLT-3 signal may be sent in the differential mode in both directions and an IEC-60958
signal may be sent in the common mode from Sink to Source. When both HEAC+/- lines are biased to a Low
level or the HEAC+/- lines are at different bias levels, no MLT-3 differential signal or IEC-60958 common
mode signal shall be transmitted. In single mode, ARC transmission is possible irrespective of the level of
HPD. However, HPD should not be changed while the ARC single mode transmission is activated to prevent
crosstalk noise from disturbing the HEAC+. HPD should not be changed while ARC common mode
transmission is activated. For HPD requirements while HEC transmission is activated, see HEAC 3.1.3 and
HEAC 3.2.2. Sources shall keep +5V Power at High level while HEC and/or ARC common mode transmission
is activated.
HEAC Table 2-10 Required Transmission Conditions
Transmission Signal
Required Condition
HEC
HEAC+ = High , HEAC- = High, +5V Power = High
ARC (Common mode)
HEAC+ = High , HEAC- = High, +5V Power = High
ARC (Single mode)
HEAC+ = ARC (Single mode), HEAC- = normal HPD
Signal, +5V Power = High
HEAC 2.5
Differential Signal Characteristics
For HEC, the input and output (I/O) drivers and differential lines are AC coupled. HEAC Figure 2-4 prescribes
the eye pattern for the transmission line and also applies to the transmitter and receiver. Sink devices that are
capable of transmitting an IEC 60958-1 signal in ARC Common Mode shall comply with these requirements
when IEC 60958-1 transmission is on, and also when IEC 60958-1 transmission is off.
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HEAC Figure 2-4 Illustration of the HEAC Differential Signal
The differential high level voltage for Vep and the low level voltage for Vem are shown in HEAC Figure 2-4.
Vec is the midpoint voltage.
HEAC Table 2-11 Differential Transmission Characteristics at TP1 and TP2
Item
Value
High Level voltage, Vep
0.2 Volts 10%
Low Level voltage, Vem
-0.2 Volts 10%
Center Level voltage ,Vec
0 Volts 20mV
Rise time / fall time (10%-90%)
3.0ns < Tr / Tf < 5.0ns
Jitter Max
1.4ns
Cycle time
8 ns ±0.125 ns
To verify the output signal at the transmitter meets the specification, subtract the reflected signal from the
actual transmitted signal.
The waveform characteristics are measured at TP1 on the Source and are measured at TP2 on the Sink as
shown in HEAC Figure 2-5. If the equipment is capable of transmitting in common mode, then during
simultaneous differential mode and common mode signaling, the differential mode specification shall be met.
Rise/Fall times are defined as the signal transition time between 10% and 90% of Vec to Vep and Vec to Vem.
The Jitter measurement is performed by measuring the center of Vep and Vec, and center of Vem and Vec.
Regarding the receiver waveform, the cable insertion loss lower limit from the cable assembly characteristics
in section HEAC 2.9 is used and it may cause worst-case signal degradation.
The Actual Measurement Conditions are measured on the load condition in HEAC Figure 2-5.
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TP1
+5V Power
HDMI Source
1.2kΩ
HEAC-
5.1kΩ
10uH
1uF
1.2kΩ
HEAC
TX/RX
10uH
5.1kΩ
Termination
Resistance
Redt
HEAC+
1uF
TP2
+5V Power
HDMI Sink
1uF
HEAC-
Termination
Resistance
Redt
HEAC
TX/RX
1uF
HEAC+
HEAC Figure 2-5 Differential Signal Test Point
HEAC 2.6
Common Mode Signal Characteristics
The common mode signal as defined in this section, regardless of how the differential signal was transmitted,
shall be correctly received.
For ARC common mode transmission, the HDMI Sink transmits an IEC 60958-1 stream as a common mode
signal component of the HEAC signal pair, in one direction (from HDMI Sink to HDMI Source), with some
adaptations to the physical layer of the unbalanced line transmission format of IEC 60958-1 (such as
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amplitude level, impedance and DC bias). This signal component shall comply with following requirements.
Sink devices that are capable of transmitting an MLT-3 signal, shall comply with these requirements whether
an MLT-3 signal exists or not. To verify that the output signal at the transmitter meets the specification, sum
the signals from the actual transmitted HEAC+/- signals and multiply the amplitude of the sum by half. The
differential signal as defined in section HEAC 2.4, regardless of how the common mode signal was transmitted,
shall be correctly received.
+Vei-swing
Veh
+Vei-swing
-Vei-swing
-Vei-swing
HEAC Figure 2-6 HEAC Common Mode Signal on each HEAC+/- Line
HEAC Table 2-12 HEAC Common Mode Transmission Characteristics at TP2
Item
Value
Termination supply voltage, Veh
4.0 Volts 10%
High level voltage, +Vei-swing
0.2 Volts 20%
Low level voltage, -Vei-swing
-0.2 Volts 20%
Rise time / fall time
When accompanied by MLT-3 signals;
Min 10ns, Max See IEC 60958-1
When not accompanied by MLT-3 signals;
Max See IEC 60958-1
Jitter Max
See IEC 60958-1
Clock frequency
4.096MHz ±1000 ppm, 5.6448MHz ±1000 ppm,
6.144MHz ±1000 ppm
(Other frequencies defined in IEC 60958-3 are
optional. Refer to HEAC 4.2.)
The waveform is measured at TP2 on the HDMI Sink as shown in HEAC Figure 2-7. If the equipment is
capable of transmitting in differential mode, then also during simultaneous differential mode and common
mode signaling, the common mode specification shall be met.
HEAC Table 2-12 specifies the output signal characteristics which are illustrated in HEAC Figure 2-6. HEAC
Table 2-13 shows the input signal characteristics after the transmission path. ARC receivers shall be capable
to receive the common mode input waveform's characteristics which are shown in HEAC Table 2-13. These
waveform characteristics are defined at Source side TP1.
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HEAC Table 2-13 HEAC Common Mode Transmission Characteristics at TP1
Item
Value
Input voltage level,
3.36 Volts <= Vheac <= 4.64 Volts
Minimum input (peak-to-peak)
160 mV （See IEC 60958-1 with Vmin=160mV）
Maximal input (peak-to-peak)
480 mV
Receiver jitter tolerance
See IEC 60958-1
The ground reference is the DDC/CEC Ground signal.
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HEAC Figure 2-7 Common Mode Signal Test Point
HEAC 2.7
Single Mode Signal Characteristics
For ARC single mode transmission, the HDMI Sink transmits an IEC 60958-1 stream as a single mode
component of the HEAC signal on the HEAC+ Line only, in one direction (from HDMI Sink to HDMI Source),
with some adaptations to the physical layer of the unbalanced line transmission format of the IEC 60958-1
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(such as impedance and DC bias). The single mode transmission case shall not be transmitted simultaneously
with differential mode transmission.
Vel swing
-
Vel
HEAC Figure 2-8 ARC Single Mode Signal on HEAC+
HEAC Table 2-14 HEAC Single Mode Transmission Characteristics at TP2
Item
Value
Termination Supply Voltage, Vel
0 ≦Vel ≦5.0 Volts
Signal amplitude, Vel swing
0.5 Volts 0.1 Volts
Rise time / fall time
Max See IEC 60958-1
Output impedance, Rest
55 ohm 35% from 0.1 MHz to 128 times the
maximum frame rate
Jitter Max
See IEC 60958-1
Clock frequency
4.096MHz ±1000 ppm, 5.6448MHz ±1000 ppm,
6.144MHz ±1000 ppm
(Other frequencies defined in IEC 60958-3 are
optional. Refer to HEAC 4.2.)
Measure the waveform at TP2 on the Sink as shown in HEAC Figure 2-9.
HEAC Table 2-14 specifies the output signal characteristics. HEAC Table 2-15 shows the received signal
characteristics after the transmission path. ARC receivers shall be capable to receive the single mode input
waveform's characteristics which are shown in HEAC Table 2-15. These waveform characteristics are defined
at Source side TP1.
HEAC Table 2-15 HEAC Single Mode Transmission Characteristics at TP1
Item
Value
Input HEAC+ Voltage Level, Vheac+
-0.3 Volts <= Vheac+ <= 5.3 Volts
Minimum input (peak-to-peak)
See IEC 60958-1
Maximal input (peak-to-peak)
See IEC 60958-1
Receiver jitter tolerance
See IEC 60958-1
The ground reference is the DDC/CEC Ground signal.
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HEAC Figure 2-9 Single Mode Signal Test Point
HEAC 2.8
Receiver Performance
The HEAC signals are composed of MLT-3 signals in differential mode, a single IEC 60958-1 signal in
common mode, or a single IEC 60958-1 signal in single mode.
Each allowed combination of transmission (HEC transmission only, ARC transmission only, or HEC
transmission with ARC transmission in common mode) may be present. In an HDMI Source or Sink device
that supports both HEC and ARC, during simultaneous common mode and differential mode signaling,
common mode and differential mode signals shall be received by the HDMI Source and differential mode
signals shall be received by the HDMI Sink. When transmitting differential and common mode signals
simultaneously, a voltage waveform example is shown in HEAC Figure 2-10.
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HPD=Low
Version 1.4b
HPD=High
4.4V
4.3V
4.2V
4.1V
4.0V
3.9V
3.8V
3.7V
3.6V
HEAC+
HEAC-
Common Mode
Signal=High
0.2
0.1
0
-0.1
-0.2
Common Mode
Signal=Low
Common Mode
Signal=High
HEAC Figure 2-10 Simultaneous Transmission Waveform
A Source device with support for receiving ARC transmission shall be capable of receiving both common
mode and single mode transmission. Given the cable characteristics as defined in HEAC 2.9, the worst case
waveform at the input terminal is estimated, and the receiver shall be capable of receiving it.
For HEAC devices applying HEC, both the HDMI Source and Sink become input terminals, hence both
devices shall meet the impedance specification for the HEAC +/- lines.
With the impedance measurement, there may be an impedance disturbance due to the connector. In
comparison to a TDMS signal, which may become skewed, the HEAC signal line carrying an IEC 60958-1
signal is of a much lower frequency and the effect of the impedance fluctuation may be ignored.
HEAC Table 2-16 HEAC Impedance Characteristics
Item
Value
TDR Rise Time (10%-90%)
1ns
Through connection differential impedance except connector area*
100 ohms 15%
At Termination differential impedance
100 ohms 10%
At Termination common mode impedance
30 ohms 20%
At Termination single mode impedance
55 ohms 35%
* A single excursion is permitted out to a max/min of 100 ohms +/- 25% and of a duration less than 250 ps.
In HEAC Table 2-16, the differential impedance is specified for the DUT’s MLT-3 transmission. The common
mode impedance is specified for the DUT’s IEC 60958 transmission in common mode. The single mode
impedance is specified for the ARC Receiver DUT’s IEC 60958 transmission for single mode. A device with
support for receiving ARC transmission (ARC Rx) shall meet the common mode and single mode impedance
specifications of HEAC Table 2-16.
HEAC 2.9
Cable Assembly Characteristics
This section describes the additional performance requirements for all Category cables with HEAC. A
Category 1/2 HDMI cable with HEAC shall meet all cable specifications as specified in Sections 4.1 and 4.2.6
of the HDMI specification, as well as all requirements in this section. The Category 1/2 HDMI cable with HEAC
is required when transmitting HEC only or HEC with common mode ARC, and is recommended for common
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mode ARC without HEC. The HDMI Category 1/2 with HEAC cable specification fully satisfies the HDMI
Category 1/2 cable specification; all requirements from the HDMI Category 1/2 cable specification shall be
fulfilled.
The HEAC+/- lines are a shielded twisted pair in the cable and used as signal lines. This twisted pair uses the
CEC/DDC ground as a shield.
With the cable impedance measurement, there may be an impedance disturbance due to the connector. In
comparison to a TDMS signal, which may become skewed, the HEAC signal line carrying an IEC 60958-1
signal is of a much lower frequency and the effect of the connector's impedance perturbation may be ignored.
Common mode impedance is the impedance of the in-phase signal when applied to the HEAC+/- lines.
HEAC Table 2-17 HEAC+/- Lines Cable Assembly
Parameter
Value
Maximum Cable Assembly Intra-Pair Skew
111ps
Differential Attenuation
300kHz - 10MHz
10MHz – 100MHz
100MHz – 200MHz
See HEAC Figure 2-11
<1.6dB
<5dB
<7.1dB
Differential Impedance*
Connection point and transition area: Up to 1ns
Cable area: 1ns – 2.5ns
Common mode Impedance*
Cable area: 1ns – 2.5ns
100 ohms 15%*
100 ohms 10%
30 ohms 20%
* A single excursion is permitted out to a max/min of 100 ohms +/- 25% and of a duration less than 250 ps.
The upper limit of the cable's differential insertion loss is shown in the formula below. The cable’s maximum
attenuation is shown in the formula below and the specification values shown in HEAC Table 2-17 shall be
fulfilled. In HEAC Figure 2-11, the solid line indicates the specification’s value. In HEAC Figure 2-11 the
dashed line expresses the formula. The formula below shows the attenuation limit value. A cable which meets
the differential attenuation requirements also satisfies necessary attenuation characteristics for common mode
transmission.
ATTmax = max( A・
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Attenuation Limits
Frequency [MHz]
0
50
100
150
200
0
1
1.6
2
3
4
5
Loss [dB]
5
6
7.1
7
8
HEAC Figure 2-11 HEAC Signal-Line Differential Insertion Loss
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HEAC 3
Version 1.4b
Capability Discovery and Control
In order to use the HDMI Ethernet Channel capabilities of HEAC, it is necessary to discover and control the
capabilities of devices in the respective paths. This is done using CDC, Capability Discovery and Control
messages carried by CEC (Supplement 1). A device with HDMI Ethernet Channel capability shall support
CDC and shall not utilize HDMI Ethernet Channel data transmissions toward any HDMI devices without the
procedures specified in this section.
HEAC 3.1
Protocol General Rules
CDC devices shall be compliant with the CEC specification (Supplement 1) with the following exceptions:
Devices implementing CDC only (CDC-only devices) shall not have a device-specific CEC Initiator
Logical Address. Such devices shall use the Initiator CEC Unregistered Logical Address (15).
Devices implementing CDC only (CDC-only devices) shall not implement any of the CEC Features.
All CDC messages shall be broadcast using a Destination Logical Address of 15 (the CEC Broadcast
Logical Address).
CEC line arbitration for CDC messages commences with the leading edge of the Start Bit and
continues until the end of the Initiator Physical Address within the second CEC operand block (see
HEAC Figure 3-1). During this period the initiator shall monitor the CEC line and if whilst in high
impedance state it detects low impedance at other than the Acknowledge bits then it shall assume that
it has lost arbitration to a second initiator and it shall immediately stop transmitting and become a
follower. The device shall then wait for the CEC line to be inactive for the signal free time period (see
Supplement 1), before attempting to send another message. This process gives priority to the logical
address with the most leading zeros. If the logical addresses are matching it gives priority to CEC
broadcast messages over CDC messages; within CDC messages it gives higher priority to the initiator
physical address with the most leading zeros.
A device that implements CEC as well as CDC shall use an Initiator Logical Address allocated according to
Supplement 1 and shall implement at least the mandatory items described in the CEC specification
(Supplement 1) in addition to the items described in this Supplement 2.
CDC messages shall be based on the CEC message frame with the following extensions (see HEAC Figure
3-1):
CDC messages shall always use a CEC opcode value of 0xF8. This CEC opcode value for CDC
messages is specified in the CEC specification (Supplement 1).
CDC messages shall always incorporate the Initiator Physical Address in the first and the second
operand block of the respective CEC message.
CDC messages shall always incorporate the CDC opcode in the third operand block of the respective
CEC message.
Specific to the CDC opcode, CDC messages shall incorporate a minimum of 0 and a maximum of 11
CDC parameters in the fourth to the fourteenth operand block of the respective CEC message.
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Start Bit
Version 1.4b
1 Block
1 Block
2 Blocks
1 Block
0 ~ 11 Blocks
CEC Header
Block
CEC Opcode
Block (0xF8)
Initiator
Phy. Address
CDC Opcode
CDC
Parameters
CDC Arbitration
HEAC Figure 3-1 CDC message frame
All numbers greater than one byte are transmitted as bytes in big endian format.
All bit sequences are sent most significant bit first.
HEAC 3.1.1
Maximum Response Time
A certain Maximum Response Time to respond to received messages shall be obeyed at the application level.
This Maximum Response Time has a desired maximum of 200ms and a required maximum of 1 second with
one exception in the case where a device responds by sending a <CDC_HEC_Report_State> message and
the CEC line is saturated by other CEC or CDC messages. In this case it is exceptionally allowed to respond
at the first opportunity after 1 second has already passed. Note that devices waiting for incoming
<CDC_HEC_Report_State> messages take appropriate measures to be able to receive also these late
arriving messages.
HEAC 3.1.2
Error Code
A CDC message is a CEC broadcast message and therefore the CEC <Feature Abort> mechanism cannot be
used. Alternatively CDC devices may report using the [CDC Error Code] field with the following errors:
“Initiator does not have the requested Capability”: the device sending this message never supports
this Capability.
“Initiator is incapable to carry out the request in this state”: the device sending this message supports
this Capability, but is incapable to carry out the request in the current state
“Other Error”: the device sending this message discovered an error not covered by one of the above
two responses.
These notifications are carried in the [CDC Error Code] fields in some CDC messages.
HEAC 3.1.3
Physical HPD pin
HDMI Sinks that support HEC shall meet the requirements of this section, since they shall support CDC (see
introduction of HEAC 3). These Sinks maintain the physical HPD pin high in order not to disturb HEC
transmission.
CDC can also be used in certain HDMI Sinks that do not support HEC, e.g. since they want to employ
CDC_HPD.
The requirements in this section are relevant for both types of Sinks.
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HDMI Sinks that support CDC hold the physical HPD pin high because an HDMI Source connected to the
HDMI Sink utilizes CDC messages that depend on Physical Address.
HDMI Sinks that support CDC shall keep the physical HPD pin high,
when connected to an HDMI Source that supports CDC messages,
o The HDMI Sink shall verify such CDC support by sending at least one CDC message to the
adjacent Source and detecting a CDC response within the Maximum Response Time.
except as needed to meet the requirement that the Hot Plug Detect pin may be asserted only when
the +5V Power line from the Source is detected (Section 8.5 of the main specification),
with the additional exceptions that HDMI Sinks that do not support the CDC_HPD feature:
o shall set the physical HPD-pin low while the E-EDID is not available for reading, and
o shall set the physical HPD-pin low a short period that is at least 100 msec when the
contents of the E-EDID is changed (see main specification Section 8.5),
Note: In the current version of Supplement 2, all CDC devices support the CDC_HPD feature.
In future releases, some CDC devices might not support the CDC_HPD feature.
with the additional exceptions that HDMI Sinks that support the CDC_HPD feature shall set the
physical HPD-pin low for a short period that is at least 100 msec (see main specification Section
8.5) in the following two cases:
o it changes the Physical Address in the HDMI VSDB of its own EDID presented to the
Source;
o it receives no response or an Error response after sending a <CDC_HPD_SetState>
message (see HEAC 3.2.2.2).
HEAC 3.2
Feature Description
HEAC 3.2.1
HDMI Ethernet Channel
HEAC 3.2.1.1
Messages
The following messages are used for the capability discovery and control of the HDMI Ethernet Channel
(HEC) of HEAC. For details of which messages are mandatory, see HEAC Table 3-4, HEAC Table 3-6 and
HEAC Table 3-7.
<CDC_HEC_InquireState>, <CDC_HEC_ReportState>, <CDC_HEC_SetState>,
<CDC_HEC_RequestDeactivation>, <CDC_HEC_NotifyAlive>, <CDC_HEC_Discover>,
<CDC_HEC_SetStateAdjacent>
HEAC 3.2.1.2
Channels, Channel States and State Transitions
Depending on the complexity of an HDMI network there are several possibilities to establish an HDMI Ethernet
Channel between two or more devices within this network. HEAC Table 3-1 shows all possible HECs and the
devices involved (red colored and bold) within a certain HDMI network. It is important to note that several of
these possible HECs might be simultaneously active within one HDMI network. It is also important to note that
the same possible HEC might be activated more than once by different Activators. An HEC is identified by the
two devices at both ends of that HEC in the appropriate CDC messages. These two devices are referred to as
the Terminating Devices of that HEC.
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HEAC Table 3-1 Possible HECs within a certain HDMI network
Terminating Devices:
1.0.0.0 and 0.0.0.0
Terminating Devices:
0.0.0.0 and 2.0.0.0
Terminating Devices:
2.0.0.0 and 2.1.0.0
Terminating Devices:
2.0.0.0 and 2.2.0.0
Terminating Devices:
1.0.0.0 and 2.0.0.0
Terminating Devices:
0.0.0.0 and 2.1.0.0
Terminating Devices:
0.0.0.0 and 2.2.0.0
Terminating Devices:
2.1.0.0 and 2.2.0.0
Terminating Devices:
1.0.0.0 and 2.1.0.0
Terminating Devices:
1.0.0.0 and 2.2.0.0
Each HEC channel may be in one of the states described in HEAC Table 3-2.
HEAC Table 3-2 HEC Channel States
HEC Channel State
Description
Potential HDMI Ethernet
Channel (PHEC)
A Potential HDMI Ethernet Channel (PHEC) shall be considered as being a channel within
an HDMI network that might provide an interconnect among two or more devices via HEC
Functionality, regardless of whether or not all devices’ HDMI connections that are part of
this channel are capable of HEC Functionality. A device shall be considered to be part of a
PHEC if it has at least one HDMI connection which is part of the PHEC. A maximum of two
HDMI connections on a device may be part of the same PHEC.
Verified HDMI Ethernet
Channel (VHEC)
A Potential HDMI Ethernet Channel (PHEC) shall be considered as a Verified HDMI
Ethernet Channel (VHEC) after a successful capability inquiry of the PHEC or a capability
discovery has shown that all devices’ HDMI connections that are part of the PHEC are
capable of HEC Functionality, regardless of whether or not the devices' HEC Functionality
is activated or deactivated.
Active HDMI Ethernet
Channel (AHEC)
A Verified HDMI Ethernet Channel (VHEC) shall be considered to be an Active HDMI
Ethernet Channel (AHEC) after successful activation of the HEC Functionality of all
devices’ HDMI connections that are part of that VHEC. The Activator of a certain AHEC
shall be the device that has sent the appropriate <CDC_HEC_SetState> message to
activate the VHEC.
HEAC Figure 3-2 provides an overview about channel states and possible state transitions.
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HEAC Figure 3-2 HEC Channel State Transition Diagram
HEAC 3.2.1.3
HEC Capability Discovery
All HDMI devices that support HEC Functionality shall distinguish between three different HEC Capabilities.
The three different HEC Capabilities are HEC Functionality, Host Functionality and External Network
Connection. They are defined in HEAC Table 3-3 and illustrated as part of different devices in HEAC Figure
3-3.
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HEAC Table 3-3 HEC Capability Definition
HEC Capability
Definition
HEC Functionality
Describes the capability of a device to support communication with other devices based on
an HDMI Ethernet Channel. Note that a device might not support HEC Functionality on all
of its HDMI connections. Therefore all devices shall only claim HEC Functionality support
for HDMI connections on which HEC Functionality is supported.
Host Functionality
Describes the capability of a device to receive or send MAC frames from or to a network
based on HDMI Ethernet Channels. It can be assumed that there is a high possibility that a
device with Host Functionality has an application layer which handles the appropriate
messages incorporated in the MAC frames. A device shall not claim Host Functionality if it
does not support HEC Functionality.
External Network
Connection
Describes the capability of a device to interconnect a network based on HDMI Ethernet
Channels with an External Network by MAC frame forwarding between both networks. A
device shall not claim External Network Connection if it doesn’t support HEC Functionality.
HEAC Figure 3-3 Devices with different HEC Capabilities
Note: Type e1, e2 and e3 are defined in HEAC 5.4.
A device within an HDMI network may discover the HEC Capabilities of all other devices within that HDMI
network by sending a <CDC_HEC_Discover> message. It is important to note that the usage of
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<CDC_HEC_Discover> messages might put a heavy load on the CEC bus. Therefore the HEC Capability
Discovery should only be used in appropriate cases e.g. at service requests. Initiators of
<CDC_HEC_Discover> messages shall not send these messages more often than once every 3 minutes with
the exception of Frame Re-transmissions when a valid frame is considered lost (see Supplement 1).
On reception of a <CDC_HEC_Discover> message, all devices within the HDMI network shall check if they
support HEC Functionality. All devices that do not support HEC Functionality (whether temporarily or never)
shall not respond. All devices that support HEC Functionality on at least one HDMI connection shall respond
with a <CDC_HEC_ReportState> message within the Maximum Response Time (see HEAC 3.1.1) to the
discovering device, regardless of whether or not the HEC Functionality is active or inactive. Note that even if
the discovering device supports HEC Functionality itself, it should not send a <CDC_HEC_ReportState>
message in response to its own <CDC_HEC_Discover> message. The <CDC_HEC_ReportState> message
shall incorporate the [HEC Support Field] parameter in order to indicate on which HDMI connections of the
initiating device HEC Functionality is supported.
After sending the <CDC_HEC_Discover> message the discovering device shall monitor
<CDC_HEC_ReportState> messages containing its [Physical Address] as the Target address for the
Maximum Response Time and it shall continue to monitor for the Maximum Response Time (reset of timeout)
after each reception of such a message until timeout or until the maximum monitoring time of 5 seconds is
reached. After monitoring for the aforementioned messages the discovering device has gathered all
information needed to determine the HEC Capabilities (see HEAC Table 3-3) of all other devices within the
HDMI network. Note that the discovering device shall not rely on a certain order of incoming
<CDC_HEC_ReportState> messages.
Unlike the response to a <CDC_HEC_InquireState> message which indicates HEC support only if all HDMI
connections of a device that are part of the respective PHEC support HEC Functionality, the response to a
<CDC_HEC_Discover> message indicates HEC Functionality if at least one HDMI connection of a device
supports HEC Functionality. Therefore <CDC_HEC_ReportState> messages which are sent in response to a
<CDC_HEC_Discover> message shall incorporate the [HEC Support Field] parameter that indicates on which
HDMI connections of a device HEC Functionality is supported. After monitoring for <CDC_HEC_ReportState>
messages as described above, the discovering device has gathered all information needed to determine if all
devices within a particular PHEC are capable of HEC Functionality on all HDMI connections which are part of
that particular PHEC. Only if all HDMI connections of all devices within a PHEC are capable of HEC
Functionality that PHEC shall be considered as a Verified HEC (VHEC) and may be activated as described
under HEAC 3.2.1.4.
HEAC Figure 3-4 and HEAC Figure 3-5 provide an example of a Capability Discovery used in a certain HDMI
network incorporating devices with different HEC Capabilities.
0.0.0.0
1.0.0.0
HEC Functionality (Active)
Host Functionality (Inactiv e)
External Network Connection (Inactive)
2.0.0.0
2.1.0.0
HEC Functionality (Ac tive)
External Network Connec tion (Active)
2.2.0.0
HEC Functionality (Inactive)
Host Functionality (Inactive)
HEAC Figure 3-4 Network example incorporating devices with different HEC Capabilities
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HEAC Figure 3-5 Discovery of all HEC capable devices and their Capabilities
CDC supports a Capability Notification to decrease the usage of <CDC_HEC_Discover> messages to only
appropriate cases. All devices within an HDMI network that support HEC Functionality shall notify all other
devices by sending <CDC_HEC_ReportState> messages with the physical address F.F.F.F as the Target
address and with incorporated [HEC Support Field] parameter whenever it discovers a new Physical Address
(e.g. at hot-plug or at mains-power-on) and whenever one of its HEC capabilities change in one of the
following ways:
[HEC State] changed from “HEC Not Supported” to either “HEC Inactive” or “HEC Active”, or vice
versa if possible (it might be not possible e.g. after unplugging the device's power or unplugging from
the HDMI network by cable removal; see also HEAC Figure 3-14 regarding safety mechanism)
[HEC State] changed in any way between “Ext Con Not Supported”, “Ext Con Inactive” and “Ext Con
Active”
[HEC State] changed in any way between “Host Not Supported”, “Host Inactive” and “Host Active”
0.0.0.0
1.0.0.0
<CDC HEC Report State>
[“F.F.F.F“][HEC State][HEC Support Field]
2.0.0.0
2.1.0.0
2.2.0.0
2.2.0.0 notifies its HEC capability
HEAC Figure 3-6 Capability Notification
HEAC 3.2.1.4
HEC Control
Devices capable of HEC Functionality may make an inquiry of the capability of a Potential HDMI Ethernet
Channel (PHEC) by sending a <CDC_HEC_InquireState> message. The PHEC that is inquired shall be
indicated by the [Physical Address] parameters within the <CDC_HEC_InquireState> message. The physical
address parameters shall define the Terminating Devices at both ends of the PHEC to be inquired whereas
the order of the physical address parameters is not specified (i.e.
<CDC_HEC_InquireState>[“1.0.0.0”][“2.2.0.0”] and <CDC_HEC_InquireState>[“2.2.0.0”][“1.0.0.0”] shall
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inquire the same PHEC). A device which is part of a PHEC shall not inquire that PHEC if it is not capable of
HEC Functionality on all HDMI connections that are part of the PHEC.
On reception of a <CDC_HEC_InquireState> message, all devices within the HDMI network that implement
HEC Functionality shall check if they are part of the PHEC to be inquired. All devices which are not part of the
PHEC to be inquired shall not respond. All devices which are part of the PHEC to be inquired shall respond
with a <CDC_HEC_ReportState> message without the [HEC Support Field] parameter within the Maximum
Response Time (see HEAC 3.1.1) to the inquiring device. The <CDC_HEC_ReportState> message indicates
whether the device is capable of HEC Functionality, whether its HEC Functionality is active, or an error code.
A device shall only respond as being capable of HEC Functionality if all its HDMI connections that are part of
the PHEC are capable of HEC Functionality. Devices that do not respond with a <CDC_HEC_ReportState>
message within the Maximum Response Time shall be considered as currently incapable of HEC Functionality.
Note that even if the inquiring device is a part of the PHEC itself, it shall not send a <CDC_HEC_ReportState>
message in response to its own <CDC_HEC_InquireState> message.
After sending the <CDC_HEC_InquireState> message, the inquiring device shall monitor
<CDC_HEC_ReportState> messages containing its [Physical Address] as the Target address for the
Maximum Response Time and it shall continue to monitor for the Maximum Response Time (reset of timeout)
after each reception of such a message until timeout, until the maximum monitoring time of 5 seconds is
reached, or until all devices which are part of the inquired PHEC have responded. After monitoring for the
aforementioned messages the inquiring device has gathered all information needed to determine if all devices
within the PHEC are capable of HEC Functionality. Only if all devices within the PHEC are capable of HEC
Functionality the PHEC shall be considered as a Verified HEC (VHEC). Note that the inquiring device shall not
rely on a certain order of incoming <CDC_HEC_ReportState> messages.
HEAC Figure 3-7 HEC capability and state inquiry
In some situations, e.g. after a service request, a device might want to activate one or more Verified HDMI
Ethernet Channels (VHECs). A simultaneous activation of multiple VHECs usually decreases the time
necessary for the activation as well as the load on the CEC bus in comparison to successive single activations
of each VHEC. Therefore, if more than one VHEC shall be activated the Activator shall use an activation
method which uses the lowest number of activation messages possible. Note that the activation method
described in this section can activate a minimum of one and a maximum of four VHECs simultaneously. Also
note that a simultaneous activation of VHECs is only possible in the case that all the VHECs share one
common Terminating Device with the same physical address (e.g. device “0.0.0.0” in HEAC Figure 3-10).
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A device may only activate those PHECs that have been verified as VHECs and shall not try to activate
PHECs that have not been verified as being VHECs nor just its own HEC Functionality. It shall activate one or
more VHECs by sending a <CDC_HEC_SetState>[PA][PA][“Activate HEC”][PA][PA][PA] message. The
VHECs to be activated shall be indicated by the physical address parameters. For each VHEC the first [PA]
parameter in the message indicates the common Terminating Device. The other Terminating Device of each
VHEC shall be indicated by the second through the last [PA] parameter. Note that the number of [PA]
parameters in the <CDC_HEC_SetState> message indicates the number of VHECs to be activated (e.g. four
[PA] parameters indicate three VHECs to be activated). Immediately after sending the activation message, if
the activating device is part of one or more VHECs to be activated it shall activate its own HEC Functionality
only on its HDMI connections that are part of the VHECs to be activated. A device shall not attempt to activate
VHECs before the device has finished all previous activation attempts (with the exception of Frame
Re-transmissions when a valid frame is considered lost (see Supplement 1)). Note that in this respect an
activation attempt shall be considered finished after the Maximum Response Time corresponding to that
activation has finally elapsed. A device shall not attempt to activate the same VHEC more than once without
interleaving the activation attempts with deactivations of the active HEC (AHEC). A device which is part of a
VHEC shall not activate that VHEC if it is not capable of activating its own HEC Functionality on all HDMI
connections that are part of that VHEC.
On reception of a <CDC_HEC_SetState>[PA][PA][“Activate HEC”][PA][PA][PA] message all devices within
the HDMI network which implement HEC Functionality shall check if they are part of at least one VHEC to be
activated. All devices which are not part of at least one VHEC to be activated shall not respond. All devices
that are part of one or more VHECs to be activated shall, immediately after activation message reception,
activate their HEC Functionality only on the HDMI connections that are part of these VHECs (even when not
fully powered-on e.g. in standby state) unless they are in an unsuitable error state. These devices shall then
immediately respond to the activating device with a <CDC_HEC_ReportState> message without the [HEC
Support Field] parameter, indicating its HEC Functionality status: HEC Functionality is activated, or an error
code. All devices which are part of more than one VHEC to be activated and which have successfully
activated their HEC Functionality regarding at least one VHEC, shall incorporate the [HEC Activation Field]
parameter into the <CDC_HEC_ReportState> message and shall set the [HEC Functionality State] parameter
to [“HEC Activation Field”]. Devices that have activated their HEC Functionality shall store the AHECs
(physical addresses of both Terminating Devices) and the Activator (physical address of the Activator device).
Devices which do not respond with a <CDC_HEC_ReportState> message within the Maximum Response
Time (see also HEAC 3.1.1) shall be considered as currently incapable of HEC Functionality. Note that even if
the Activator itself is part of a VHEC to be activated, it shall not send a <CDC_HEC_ReportState> message in
response to its activation message. If a device’s HEC Functionality is already activated at the activation
message reception time, the device shall keep its HEC Functionality activated and if it is part of VHECs to be
activated it shall store the appropriate AHECs (physical addresses of both Terminating Devices) and the
Activator (physical address of the Activator device) in addition to previously stored AHECs and Activators.
After sending the activation message, the Activator shall monitor the <CDC_HEC_ReportState> messages
containing its [Physical Address] as the Target address for the Maximum Response Time and it shall continue
to monitor for the Maximum Response Time (reset of timeout) after each reception of such a message until
timeout, or until the maximum monitoring time of 5 seconds is reached, or until all devices which are part of the
VHECs have responded. After monitoring for the aforementioned messages, the Activator has gathered all
information required to determine if the activation of the VHECs has been successful. A VHEC that is
successfully activated shall be considered as an Active HDMI Ethernet Channel (AHEC). The activation
device of the AHEC shall be considered as the Activator and shall maintain its state as the Activator of that
AHEC (physical addresses of both Terminating Devices). Note that all AHECs shall be considered as
stand-alone AHECs even when simultaneously activated (as if they were activated by several activation
messages containing single VHECs). If the activation of a VHEC has failed, e.g. it received a response with an
error code, received a response with an [HEC Activation Field] parameter indicating that the HEC Functionality
on at least one of the appropriate HDMI ports is not activated, or missed a response from at least one device,
the Activator shall immediately send a <CDC_HEC_SetState>[PA][PA][“Deactivate HEC”] message for each
VHEC that did not properly activate to inform all devices within each such VHEC. Note that the Activator shall
not rely on a certain order of incoming <CDC_HEC_ReportState> messages.
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Channel Activation
0.0.0.0
Channel to be activated
1.0.0.0
2.0.0.0
2.1.0.0
2.2.0.0
HEAC Figure 3-8 Example for an HDMI network
HEAC Figure 3-9 Activation of an HDMI Ethernet Channel (HEC)
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Multiple VHEC Activation
0.0.0.0
1.0.0.0
Version 1.4b
2.0.0.0
2.1.0.0
VHECs to be activated
2.2.0.0
HEAC Figure 3-10 HDMI network example for multiple VHEC activation
0.0.0.0 activates
multiple VHECs
MRT: Maximum Response Time
0.0.0.0
1.0.0.0
2.0.0.0
<CDC HEC SetState>[“0.0.0.0“]
[“2.2.0.0“][“Activate HEC“][“2.1.0.0“]
2.1.0.0
2.2.0.0
0.0.0.0 activates the VHECs
0.0.0.0 to 2.1.0.0, 0.0.0.0 to 2.2.0.0
< MRT
< MRT
<CDC HEC Report State> [“0.0.0.0“][“HEC Active“]
[“Host Active“][“Ext Con Not Supp.“][“No Error“]
2.1.0.0 confirms that its
HEC Functionality is active
<CDC HEC Report State> [“0.0.0.0“][“HEC Activation
Field“][“...“][“...“][“No Error“][HEC Activation Field]
2.0.0.0 confirms that its
HEC Functionality is active
<CDC HEC Report State> [“0.0.0.0“][“HEC Active“]
[“Host Active“][“Ext Con Not Supp.“][“No Error“]
2.2.0.0 confirms that its
HEC Functionality is active
< MRT
All devices responded: 0.0.0.0
considers VHECs as AHECs
HEAC Figure 3-11 Activation of multiple HDMI Ethernet Channel (HEC)
A device may only deactivate active HECs (AHECs) and it shall neither try to deactivate non-active VHECs nor
potential HECs (PHECs). Only the Activator of an AHEC shall be allowed to deactivate that AHEC. It shall
deactivate that AHEC by sending a <CDC_HEC_SetState>[PA][PA][“Deactivate HEC”] message. The AHEC
to be deactivated shall be indicated by the physical address parameters [PA][PA]. The physical address
parameters shall define the Terminating Devices at both ends of the AHEC to be deactivated whereas the
order of the physical address parameters is not specified (i.e.
<CDC_HEC_SetState>[“1.0.0.0”][“2.2.0.0”][“Deactivate HEC”] and
<CDC_HEC_SetState>[“2.2.0.0”][“1.0.0.0”][“Deactivate HEC”] shall deactivate the same AHEC). Immediately
after sending the deactivation message, the deactivating (sending) device does not need and shall remove all
states associated with the deactivated AHEC and its Activator and it shall deactivate its HEC Functionality on
the HDMI connections that are part of the deactivated AHEC if the appropriate HDMI connection is not part of
another AHEC. It shall not deactivate its HEC Functionality on an HDMI connection that is also part of another
AHEC but it does not need and shall remove all states associated with the deactivated AHEC and its Activator.
On reception of a <CDC_HEC_SetState>[PA][PA][“Deactivate HEC”] message each device within the HDMI
network that implement HEC Functionality shall check if it is part of the deactivated AHEC and if the message
has been sent by the device which has previously activated that AHEC, the Activator. The message shall be
ignored if it has not been sent from the Activator of that AHEC. A device which is not part of the deactivated
AHEC shall ignore the message. A device that is part of the deactivated AHEC and is not part of another
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AHEC shall immediately deactivate its HEC Functionality on the HDMI connections that are part of the
deactivated AHEC and does not need and shall remove all states associated with that AHEC and its Activator.
A device that is part of the deactivated AHEC and is also part of another AHEC shall not deactivate its HEC
Functionality on an HDMI connection that is also part of another AHEC but it does not need and shall remove
all states associated with the deactivated AHEC and its Activator.
2.1.0.0 deactivates
a channel
0.0.0.0
1.0.0.0
2.0.0.0
2.1.0.0
2.2.0.0
2.1.0.0 deactivates channel
2.2.0.0 to 0.0.0.0
<CDC HEC SetState>
[“2.2.0.0“][“0.0.0.0“][“Deactivate HEC“]
0.0.0.0 deactivates its HEC
Functionality
2.0.0.0 deactivates its HEC
Functionality
2.2.0.0 deactivates its HEC
Functionality
HEAC Figure 3-12 Deactivation of an AHEC by its Activator
A device that is part of an active HEC (AHEC) shall not autonomously deactivate its HEC Functionality (e.g. if
it’s switched to standby) in order to give the Activator the opportunity to reject the deactivation of the AHEC in
case it is still needed for an important task. Instead, it may request deactivation of its HEC Functionality
indirectly by requesting all Activators of all the AHECs that it is part of to deactivate their respective AHECs.
The device shall request indirect deactivation by sending <CDC_HEC_RequestDeactivation> messages to all
Activators of all AHECs that it is part of. Such a message shall be ignored if it has been sent to a device which
is not the Activator of that AHEC. An Activator which receives a <CDC_HEC_RequestDeactivation> message
from a device that is part of an AHEC that the Activator has activated shall check if it is appropriate to
deactivate the AHEC (it might not be appropriate, e.g., if the AHEC is used for recording). If it is appropriate to
deactivate the AHEC, the Activator shall immediately send a <CDC_HEC_SetState>[PA][PA][“Deactivate
HEC”] message incorporating the same AHEC to inform all devices within the AHEC. If it is not appropriate to
deactivate the AHEC, the Activator shall do nothing and the requestor shall not deactivate its HEC
Functionality.
HEAC Figure 3-13 Request deactivation of an AHEC by a device part of that AHEC
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It might be possible that a device is suddenly incapable of HEC Functionality, e.g. after unplugging the
device's power or unplugging from the HDMI network by cable removal. In this case the device might be
incapable of deactivating the active HECs (AHECs) that it is part of, or for which it is the Activator. To avoid a
situation that an AHEC is incorrectly deactivated, all devices that are part of at least one AHEC or are an
Activator of at least one AHEC shall send <CDC_HEC_NotifyAlive> messages every 60 to 65 seconds. Each
device shall start sending the <CDC_HEC_NotifyAlive> messages randomly (it shall not always use the same
timing) within the time frame of 10 to 50 seconds after activation of its HEC Functionality or after becoming an
Activator. <CDC_HEC_NotifyAlive> messages shall not be sent more often than once every 60 seconds from
the same initiator’s physical address with the exception of Frame Re-transmissions when a valid frame is
considered lost (see CEC Supplement 1). Note that even if a device is part of and/or Activator of multiple
AHECs it shall send only one (not multiple) <CDC_HEC_NotifyAlive> messages in this period.
A device that is part of an active HEC (AHEC) shall check for regularly received <CDC_HEC_NotifyAlive>
messages from the Activator of that AHEC. If no <CDC_HEC_NotifyAlive> message is received from the
Activator within 140 seconds after the reception of the last <CDC_HEC_NotifyAlive> message from the
Activator, the device shall designate the Activator as incapable of HEC Functionality and the AHEC is to be
deactivated. Devices that are part of the AHEC and are not part of any other AHEC shall immediately
deactivate their HEC Functionality on their HDMI connections that are part of the AHEC and do not need and
shall remove all states associated with the AHEC and its Activator. If a device is also part of another AHEC, it
shall not deactivate its HEC Functionality on an HDMI connection that is also part of another AHEC but it does
not need and shall remove all states associated with the AHEC and its Activator.
A device that is the Activator of an AHEC shall check for regularly received <CDC_HEC_NotifyAlive>
messages from all devices that are part of the AHEC. If at least one device that is part of that AHEC does not
send a <CDC_HEC_NotifyAlive> message within 140 seconds after sending the last
<CDC_HEC_NotifyAlive> message, then the Activator shall immediately deactivate the AHEC by sending a
<CDC_HEC_SetState>[PA][PA][“Deactivate HEC”] message. It shall then immediately deactivate its HEC
Functionality on the HDMI connections that are part of the deactivated AHEC if it is part of that AHEC and it
does not need and shall remove all states associated with the AHEC and its Activator. If the device is also part
of another AHEC, it shall not deactivate its HEC Functionality on an HDMI connection that is also part of
another AHEC but it does not need and shall remove all states associated with the AHEC and its Activator.
Note that the Activator shall not rely on a certain order of incoming <CDC_HEC_NotifyAlive> messages.
HEAC Figure 3-14 AHEC safety mechanism
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HEAC 3.2.1.5
Version 1.4b
HEC Control for Adjacent Devices
In some situations and for some devices it might be appropriate to activate the HEC Functionality whenever
this device joins an HDMI network, e.g. when it is powered-on or hot-plugged, and to keep the HEC
Functionality active until the device is removed from the HDMI network, e.g. when powered-off or at cable
removal. For such situations and devices it is possible to use the HEC Control for Adjacent Devices described
within this section.
A device may try to activate an HEC (either it is a potential or a verified HEC) to an adjacent device by using a
simplified method without previous verification that the HEC is a VHEC (note that the state diagram in HEAC
Figure 3-2 is not applicable for this simplified method). Using the simplified method a device may try to
activate an HEC to an adjacent device by sending a <CDC_HEC_SetStateAdjacent>[PA][“Activate HEC”]
message. The Terminating Devices of the HEC to be activated shall be the initiating device of the message
and the device indicated by the physical address parameter. A device shall not activate an HEC to an adjacent
device if it is not capable of activating its own HEC Functionality on the HDMI connection that is part of that
HEC. A device shall not attempt to activate the same HEC more than once without interleaving the activation
attempts with deactivations of the active HEC (AHEC).
On reception of a <CDC_HEC_SetStateAdjacent>[PA][“Activate HEC”] message all devices within the HDMI
network which implement HEC Control for Adjacent Devices shall check if they are part of the HEC to be
activated and if the message has been initiated from an adjacent device. All devices which are not part of the
HEC to be activated or which are not adjacent to the initiator shall not respond. A device that is part of the
HEC to be activated and that is adjacent to the initiator shall immediately activate its HEC Functionality only on
the HDMI connection that is part of that HEC after activation message reception (even when not fully
powered-on e.g. in standby state) unless it is in an unsuitable error state. This device shall then immediately
respond to the activating device with a <CDC_HEC_ReportState> message without the [HEC Support Field]
parameter, indicating its HEC Functionality status: HEC Functionality is activated, or an error code. Devices
which do not respond with a <CDC_HEC_ReportState> message within the Maximum Response Time (see
also HEAC 3.1.1) shall be considered as currently incapable of HEC Functionality. Note that even if the
Activator itself is part of the HEC to be activated, it shall not send a <CDC_HEC_ReportState> message in
response to its activation message. If a device’s HEC Functionality is already activated at the activation
message reception time, the device shall keep its HEC Functionality activated (note that also in this case the
device shall respond with a <CDC_HEC_ReportState> message).
After sending the activation message, the Activator shall monitor the <CDC_HEC_ReportState> messages
containing its [Physical Address] as the Target address for the Maximum Response Time or until the adjacent
device which is part of the HEC has responded. After monitoring for the aforementioned messages, the
Activator has gathered all information required to determine if the activation of the HEC has been successful. If
the activation of the HEC has been successful the Activator shall immediately activate its own HEC
Functionality only on its HDMI connection that is part of the activated HEC.
Note that devices which are part of HECs which have been activated using the HEC Control for Adjacent
Devices neither have to store the Terminating Devices and the Activators of these HECs nor do they have to
send <CDC_HEC_NotifyAlive> messages (contrary to the mandatory <CDC_HEC_NotifyAlive> messages
whenever a VHEC has been activated using the method described in HEAC 3.2.1.4). Note that devices which
are part of HECs which have been activated using the HEC Control for Adjacent Devices shall send
<CDC_HEC_NotifyAlive> messages as described under HEAC 3.2.1.4 if they are also part of or are an
Activator of at least one AHEC which has been activated using the method described in HEAC 3.2.1.4.
Devices which are part of HECs which have been activated using the HEC Control for Adjacent Devices shall
deactivate those HECs immediately when removed from the HDMI network, e.g. when powered-off, by
sending <CDC_HEC_SetStateAdjacent>[PA][“Deactivate HEC”] messages. The Terminating Devices of the
HEC to be deactivated shall be the initiating device of the message and the device indicated by the physical
address parameter. Immediately after sending the deactivation message, the deactivating device shall
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deactivate its HEC Functionality on the HDMI connection that is part of the HEC to be deactivated if the
appropriate HDMI connection is not part of another AHEC. It shall not deactivate its HEC Functionality on an
HDMI connection that is also part of another AHEC.
On reception of a <CDC_HEC_SetStateAdjacent>[PA][“Deactivate HEC”] message each device within the
HDMI network that implements HEC Control for Adjacent Devices shall check if it is part of the HEC to be
deactivated and if the message has been sent by an adjacent device. The message shall be ignored if it has
not been sent by an adjacent device or if the HEC was not previously activated using the HEC Control for
Adjacent Devices. A device which is not part of the HEC to be deactivated shall ignore the message. A device
that is part of the HEC to be deactivated and is not part of another AHEC shall immediately deactivate its HEC
Functionality on the HDMI connection that is part of the HEC to be deactivated. A device that is part of the
HEC to be deactivated and is also part of another AHEC shall not deactivate its HEC Functionality on an HDMI
connection that is also part of another AHEC.
In some cases, e.g. at cable removal, it might be impossible to correctly deactivate an HEC which has been
activated using the HEC Control for Adjacent Devices. All devices supporting HEC Control for Adjacent
Devices shall therefore be able to detect these cases, e.g. by monitoring the HPD and DDC lines, and they
shall immediately deactivate their HEC Functionality on the HDMI connection that is part of the deactivated
HEC at detection time.
HEAC 3.2.1.6
Best Practices
It is recommended that HEC devices provide support for an adequate number of AHECs depending on the
number of HDMI connections with HEC Functionality. Devices which have reached the maximum support of
AHECs (e.g. no further resources to store the physical addresses of the Terminating Devices and the Activator
for additional AHECs) should reply to further activation attempts of the HEC Functionality by sending a
<CDC_HEC_ReportState> message incorporating a [CDC Error Code] of [“Initiator is not capable to carry out
the request in this state”].
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HEAC 3.2.2
CDC_HPD (CDC Hot Plug Detect signal)
HEAC 3.2.2.1
Messages
The following messages are used for CDC_HPD. For details of which messages are mandatory, see HEAC
Table 3-5, HEAC Table 3-6, HEAC Table 3-7 and HEAC 3.2.2.2.
<CDC_HPD_SetState>, < CDC_HPD_ReportState>
Feature Description
HEAC 3.2.2.2
This feature allows an HDMI Sink device to enable/disable an adjacent HDMI Source device to read the EDID
or initialize content protection while maintaining the physical HPD pin asserted.
HDMI Sinks which support HEC shall support the <CDC_HPD_SetState> message as an initiator and the
<CDC_HPD_ReportState> message as a follower. HDMI Sources which support HEC shall support the
<CDC_HPD_ReportState> message as an initiator and the <CDC_HPD_SetState> message as a follower.
HDMI Sinks that support the CDC_HPD feature shall use the <CDC_HPD_SetState> message to
communicate the availability of the Sink’s EDID for reading and to initiate a content protection reset in the
Source instead of toggling the Physical HPD line. HDMI Sources that support the CDC_HPD feature shall
correctly process <CDC_HPD_SetState> messages and respond with <CDC_HPD_ReportState> messages.
The usage of these messages allows undisturbed transmission on the HEC.
Source
Sink
<CDC_HPD_SetState>[Input port number]
[“CP&EDID_DISABLE”]
Prohibit to
read EDID.
Reset CP.
Physical
HPD-pin
is High
<CDC_HPD_ReportState>
[“CP&EDID_DISABLE”][“No error”]
May change
EDID data
<CDC_HPD_SetState>[Input port number]
[“CP&EDID_ENABLE”]
Read EDID..
Start CP.
<CDC_HPD_ReportState>
[“CP&EDID_ENABLE”][“No error”]
Start to send
AV signal
HEAC Figure 3-15 Disable and Enable of reading EDID and restarting CP (1)
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A Sink shall not send a <CDC_HPD_SetState> message with any of the following three parameters unless it
supports content protection: [“CP&EDID_DISABLE”], [“CP&EDID_ENABLE”],
[“CP&EDID_DISABLE_ENABLE”]. If a Source does not support content protection, it shall execute the
equivalent EDID-only behavior on reception of a <CDC_HPD_SetState> message with any of the following
three parameters: [“CP&EDID_DISABLE”], [“CP&EDID_ENABLE”], [“CP&EDID_DISABLE_ENABLE”].
After a <CDC_HPD_SetState> message reception, only the HDMI Source adjacent to and addressed by the
initiator of that message shall respond with a <CDC_HPD_ReportState> message. If the HDMI Sink receives
a CDC_HPD Error response or there is no response to that message within the Maximum Response Time, the
HDMI Sink shall reset the Source by means of the physical HPD line. HDMI Sinks may attempt one re-try after
receipt of a CDC_HPD Error response or when there is no response to that message within the Maximum
Response Time prior to resetting the Source by means of the physical HPD line.
Note: A CDC_HPD Error response is a <CDC_HPD_ReportState> [HPD State] [“Other Errors”] message or a
<CDC_HPD_ReportState> [HPD State] [“Initiator does not have the requested Capability”] message. A source
shall not send a <CDC_HPD_ReportState> [HPD State] [“Initiator is not capable to carry out the request in this
state”].
An HDMI sink shall keep its EDID readable until a <CDC_HPD_ReportState> [“CP&EDID_DISABLE”] [“No
error”] message reception. After the reception of this message, the HDMI sink is permitted to transit to the
EDID unreadable state and within this state it may change EDID data. Prior to sending a
<CDC_HPD_SetState> [Input port number] [“CP&EDID_ENABLE”] message, the HDMI sink shall transit to
the EDID readable state.
An HDMI sink shall keep its EDID readable until a <CDC_HPD_ReportState> [“EDID_DISABLE”] [“No error”]
message reception. After the reception of this message, the HDMI sink is permitted to transit to the EDID
unreadable state and within this state it may change EDID data. Prior to sending a <CDC_HPD_SetState>
[Input number] [“EDID_ENABLE”] message, the HDMI sink shall transit to the EDID readable state.
If a Source with activated HEC Functionality does not send a TMDS video stream to the appropriate Sink, it
should reply with a <CDC_HPD_ReportState>[HPD State] [“No Error, No video stream”] message after
<CDC_HPD_SetState> message reception. In this case, the Sink should not resend the
<CDC_HPD_SetState> message so frequently.
If a Source does not receive a <CDC_HPD_SetState> [Input port number] [“CP&EDID _ENABLE”] message
within the Maximum Response Time after sending a <CDC_HPD_ReportState> [“CP&EDID_ DISABLE”][“No
Error”] message, it may resend the <CDC_HPD_ReportState> [“CP&EDID_ DISABLE”] [“No Error”] message.
HEAC Figure 3-15 indicates the usage of the <CDC_HPD_SetState> [Input port number]
[“CP&EDID_DISABLE”] and the <CDC_HPD_SetState> [Input port number] [“CP&EDID_ENABLE”] message
and the related message sequence. In order to shorten this sequence, <CDC_HPD_SetState> [Input port
number] [“CP&EDID_DISABLE_ENABLE”] may be used as indicated in HEAC Figure 3-16.
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Source
Version 1.4b
Sink
<CDC_HPD_SetState>[Input port number]
[“CP&EDID_DISABLE_ENABLE”]
Reset CP.
Read EDID.
Start CP.
<CDC_HPD_ReportState>
[“CP&EDID_DISABLE_ENABLE”]
[“No error”]
Physical HPD-pin
is High
Keep EDID readable.
Not change EDID data.
Start to send
AV signal
HEAC Figure 3-16 Disable and Enable of reading EDID and restarting CP (2)
A Sink shall keep its EDID readable even if it sends a <CDC_HPD_SetState> [Input port number]
[“CP&EDID_DISABLE_ENABLE”] message.
Note: On sending the <CDC_HPD_SetState> [Input port number] ["CP&EDID_DISABLE_ENABLE"] message,
a Sink may change the EDID data instantly while keeping the EDID readable, before the completion of this
message transmission.
HEAC 3.2.2.3
Additional Source Requirements
Sources that support <CDC_HPD_SetState> and <CDC_HPD_ReportState> shall implement the behavior
specified in this section to generate the CP&EDID_HPD signal (or state) for use by the Source’s content
protection logic. The CP&EDID_HPD signal (or state) is generated by combining state from the physical HPD
line with received <CDC_HPD_SetState> messages as indicated below.
Sources that support <CDC_HPD_SetState> and <CDC_HPD_ReportState> and that support content
protection shall maintain the state variable CP&EDID_MODE. CP&EDID_MODE shall be reset to the Enabled
state (Enabled = “High”) when the physical HPD line state is “Low.” When the physical HPD line state is “High”,
CDC messages from the Sink which set the state of CP&EDID_MODE allow notification of the state of CP
authentication and readability of the EDID to the Source device. When the physical HPD line state is “High”,
on receiving a <CDC_HPD_SetState> message with one of the following three parameters, Sources shall set
CP&EDID_MODE as follows:
CP&EDID_ENABLE
Set CP&EDID_MODE to the Enabled state (Enabled = “High”);
CP&EDID_DISABLE
Set CP&EDID_MODE to the Disabled state (Disabled = “Low”);
CP&EDID_DISABLE_ENABLE
First set CP&EDID_MODE to the Disabled state then back to the
Enabled state, with adequate time spent in the Disabled state to
guarantee the required transitions in the Source content protection
logic and to initiate a read of the Sink’s EDID by the Source.
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CP&EDID_HPD is a logical equivalent of the physical HPD line that causes the content protection logic of a
Source device (or downstream output of a Repeater device) to evaluate and possibly initiate a state transition
within the content protection logic as described in the relevant content protection specification.
CP&EDID_HPD is also used to halt reads of the Sink’s EDID (CP&EDID_HPD=”Low”) then subsequently to
initiate a read of the Sink’s EDID (CP&EDID_HPD transitions to ”High”). The CP&EDID_HPD signal (or state)
shall be generated by forming the logical AND of the state of the physical HPD line with the state of
CP&EDID_MODE as shown in the following figure:
Physical HPD Line
<CDC_HPD_SetState> [“CP&EDID_ENABLE”]
<CDC_HPD_SetState> [“CP&EDID_DISABLE”]
<CDC_HPD_SetState> [“CP&EDID_DISABLE_ENABLE”]
CP&EDID_MODE
CP&EDID_HPD
HEAC Figure 3-17 A timing example of CDC_HPD messages and CP&EDID_HPD
Sources that support <CDC_HPD_SetState> and <CDC_HPD_ReportState> shall maintain the state variable
EDID_MODE. EDID_MODE shall be reset to the Enabled state (Enabled = “High”) when the physical HPD line
state is “Low.” When the physical HPD line state is “High”, CDC messages from the Sink which set the state of
EDID_MODE allow notification of the state of readability of the EDID to the Source device. When the physical
HPD line state is “High”, on receiving a <CDC_HPD_SetState> message with one of the following three
parameters, Sources shall set EDID_MODE as follows:
EDID_ENABLE
Set EDID_MODE to the Enabled state (Enabled = “High”);
EDID_DISABLE
Set EDID_MODE to the Disabled state (Disabled = “Low”);
EDID_DISABLE_ENABLE
First set EDID_MODE to the Disabled state then back to the Enabled
state, with adequate time spent in the Disabled state to initiate a read
of the Sink’s EDID by the Source.
EDID_HPD is a logical equivalent of the physical HPD line that causes the Source device (or downstream
output of a Repeater device) to halt reads of the Sink EDID (EDID_HPD=”Low”) then subsequently to initiate a
read of the Sink’s EDID (EDID_HPD transitions to ”High”). The EDID_HPD signal (or state) shall be generated
by forming the logical AND of the state of the physical HPD line with the state of EDID_MODE as shown in the
following figure:
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Physical HPD Line
<CDC_HPD_SetState> [“EDID_ENABLE”]
<CDC_HPD_SetState> [“EDID_DISABLE”]
<CDC_HPD_SetState> [“EDID_DISABLE_ENABLE”]
EDID_MODE
EDID_HPD
HEAC Figure 3-18 A timing example of CDC_HPD messages and EDID_HPD
HDMI Sources may read EDID data of the Sink device at any time while both CP&EDID_HPD and EDID_HPD
are High, and shall not read EDID data of the Sink device when either CP&EDID_HPD or EDID_HPD is Low.
Note that CP&EDID_MODE and EDID_MODE are controlled independently.
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High-Definition Multimedia Interface Specification
HEAC 3.3
Version 1.4b
Message Descriptions
The section defines the individual messages used in CDC. It describes and defines the parameters and expected responses of these messages. As
CDC has no session layer, this section and the operands section HEAC 3.5 effectively define the complete messaging system. HEAC Table 3-4 to
HEAC Table 3-7 show which messages are mandatory. If a manufacturer implements any of the optional messages, then they shall be
implemented as described in HEAC 3.2.
The following list describes each heading within the message HEAC Table 3-4
CDC Opcode – The name used to identify the message.
Value – The unique identifier for the message.
Description – A brief description of the message.
Parameters – The set of parameters used by the message, refer to HEAC Table 3-8 for individual descriptions.
Parameter Description – A brief description of the parameters that the message uses.
Response – Describes how a device should respond on receipt of the message.
Mandatory – Indicates if it is mandatory for a device to react and respond on receipt of the message. Note that where a message is indicated
as being mandatory for ‘All’ devices. ‘HEC’ indicates a device that supports HDMI Ethernet Channel.
Within the tables some cells are intentionally left blank; this indicates that there are no associated requirements for the Opcode described.
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HEAC Table 3-4 Message Descriptions for the HDMI Ethernet Channel Feature
CDC Opcode
Value
Description
Parameters
Parameter
description
Response
Mandatory
for
Initiator
Mandatory
for
Follower
<CDC_HEC_InquireState>
0x00
Used to
inquire the
state of an
HDMI
Ethernet
Channel
[Physical Address]
Physical
Adresses of
channel’s
Terminating
Devices. The
order is not
specified.
<CDC_HEC_ReportState>
HEC
HEC
Used to
report
capabilities
and states
of a device
that
supports
HEC
Functionality
[Physical Address]
PA of Target
HEC
HEC
[HEC State]
Indicates
capabilities,
current active
status and Error
status for an
HDMI Ethernet
Channel device.
<CDC_HEC_ReportState>
0x01
[Physical Address]
[HEC Support Field]
(shall be incorporated if
and only if PA of Target
is F.F.F.F or if the
message is sent in
response to a
<CDC_HEC_Discover>
message)
[HEC Activation Field]
(shall be incorporated if
and only if the
message is sent in
response to a
<CDC_HEC_SetState>
message incorporating
more than one VHEC)
<CDC_HEC_SetStateAdjacent>
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0x02
Used to
activate or
de-activate
an HDMI
Ethernet
Channel to
an adjacent
device
[Physical Address]
[HEC Set State]
Indicates the
HEC
functionality of
all HDMI ports
independently.
Indicates
activation status
for multiple
VHECs.
Physical
Address to
channel’s
Terminating
device (not
initiator’s PA)
<CDC_HEC_ReportState>
Required State
of the HEC
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CDC Opcode
Value
Description
Parameters
Parameter
description
Response
<CDC_HEC_SetState>
0x03
Used to
activate up
to four or to
de-activate
one HDMI
Ethernet
Channel
[Physical Address]
Physical
Adresses of the
first channel’s
Terminating
Devices. The
order is not
specified if
activating only
one channel.
When activating
more than one
channel, the first
PA is common to
all VHECs to be
activated.
<CDC_HEC_ReportState>
[Physical Address]
[HEC Set State]
[Physical Address]
[Physical Address]
[Physical Address]
(The last three [PA]
parameters shall not be
incorporated if only one
HEC shall be activated.
The number of
channels to be
activated is the number
of included [PA]
parameters minus
one.)
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Mandatory
for
Initiator
Mandatory
for
Follower
HEC
Required State
of the HEC(s)
1, 2 or 3
Physical
Addresses of
channels’
Terminating
Devices
corresponding to
nd
rd
the 2 , 3 , and
th
4 channels to
be activated
(only
incorporated for
multiple VHEC
activation)
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CDC Opcode
Value
Description
Parameters
Parameter
description
Response
Mandatory
for
Initiator
Mandatory
for
Follower
<CDC_HEC_RequestDeactivation>
0x04
Used to
request the
deactivation
of an HDMI
Ethernet
Channel
[Physical Address]
Physical
Address of
Target (the
channel’s
Activator)
<CDC_HEC_SetState>
HEC
HEC
HEC
HEC
<CDC_HEC_NotifyAlive>
0x05
Used to
keep active
HDMI
Ethernet
Channels
active
<CDC_HEC_Discover>
0x06
Used to
discover all
HEC
capabilities
of devices
within the
HDMI
network
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[Physical Address]
[Physical Address]
Physical
Adresses of
channel’s
Terminating
Devices. The
order is not
specified.
<CDC_HEC_ReportState>
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HEAC Table 3-5 Message Descriptions for the CDC_HPD Feature
CDC Opcode
Value
Description
Parameters
Parameter description
Response
Mandatory
for
Initiator
Mandatory
for
Follower
<CDC_HPD_SetState>
0x10
Used to
substitute
physical
HPD pin
signaling.
[Input port number]
For this message, both
[Input port number] and
[HPD State] are packed
in one byte such that the
[Input port number] is in
the four most significant
bits and [HPD_State] is
in the four least
significant bits.
<CDC_HPD_ReportState>
Sink with
HEC
Source with
HEC
[HPD State]
The Sink’s input port
number for which the
HPD state event is
requested by the Initiator
Note: Follower’s
upstream address is
derived by combining the
input port number into
the relevant nibble of the
adjacent Initiator’s
physical address.
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CDC Opcode
Value
Description
Parameters
Parameter description
<CDC_HPD_ReportState>
0x11
Used to
report the
state of a
device
using the
CDC HPD
signaling
[HPD State]
For this message, both
[HPD State] and
[CDC_HPD_Error_Code]
are packed in one byte
such that the [HPD
State] is in the four most
significant bits and
[CDC_HPD_Error_Code]
is in the four least
significant bits.
[CDC_HPD_Error_Code]
Response
Mandatory
for
Initiator
Mandatory
for
Follower
Source
with HEC
Sink with
HEC
HPD state event
executed by an initiator.
Note: Follower’s
downstream address is
derived from Initiator’s
physical address.
The Initiator and Follower utilizing these messages shall be directly connected by an HDMI Cable and shall only use destination physical addresses
of the directly connected device.
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HEAC 3.4
Version 1.4b
Message Dependencies
This section describes the dependencies between each message. This section is divided into two tables, which describe the following:
HEAC Table 3-6 describes the message dependencies when a device is capable of receiving a particular message.
HEAC Table 3-7 describes the message dependencies when a device is capable of sending a particular message.
Each table describes the additional messages that the device shall be capable of receiving and sending if a particular message is supported.
HEAC Table 3-6 Message Dependencies when receiving a CDC message
If device responds to the following
message:
It shall not ignore the message(s):
It shall be capable of sending message(s):
<CDC_HEC_InquireState>
<CDC_HEC_SetState>
<CDC_HEC_ReportState>
<CDC_HEC_SetStateAdjacent>
<CDC_HEC_ReportState>,
<CDC_HEC_SetStateAdjacent>
<CDC_HEC_SetState>
<CDC_HEC_InquireState>
<CDC_HEC_ReportState>,
<CDC_HEC_RequestDeactivation>
<CDC_HEC_RequestDeactivation>
<CDC_HEC_ReportState>
<CDC_HEC_SetState>
<CDC_HEC_Discover>
<CDC_HEC_SetState>
<CDC_HEC_ReportState>
<CDC_HPD_SetState>
<CDC_HPD_ReportState>
HEAC Table 3-7 Message Dependencies when sending a CDC message
If device ever sends the following message:
It shall be capable to send the message(s):
It shall respond to the message(s):
<CDC_HEC_InquireState>
<CDC_HEC_SetState>
<CDC_HEC_RequestDeactivation>
<CDC_HEC_SetStateAdjacent>
<CDC_HEC_SetState>
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<CDC_HEC_SetStateAdjacent>
<CDC_HEC_InquireState>
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<CDC_HEC_RequestDeactivation>
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If device ever sends the following message:
It shall be capable to send the message(s):
It shall respond to the message(s):
<CDC_HEC_RequestDeactivation>
<CDC_HEC_ReportState>
<CDC_HEC_SetState>,
<CDC_HEC_InquireState>,
<CDC_HEC_Discover>
<CDC_HEC_ReportState>
<CDC_HEC_SetState>,
<CDC_HEC_InquireState>,
<CDC_HEC_Discover>
<CDC_HPD_ReportState>
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High-Definition Multimedia Interface Specification
HEAC 3.5
Version 1.4b
Operand Descriptions
In HEAC Table 3-8, Operand Descriptions are ordered alphabetically. Sub-operands, which only occur in a single parent operand, are grouped with
their parent and are shown indented.
Not all operand values are shown in HEAC Table 3-8: those not shown shall be considered as “reserved”.
HEAC Table 3-8 Operand descriptions for CDC messages
Name
Range Description
[CDC Error Code]
“No Error”
0x00
“Initiator does not have the requested
Capability”
0x01
The device never supports this Capability
“Initiator is not capable to carry out the
request in this state”
0x02
The device supports this Capability, but is not
capable to carry out the request in the current state
”Other Error”
0x03
Another error occurred.
“HEC Inactive”
0
“HEC Active”
1
“Reserved (0x0)”
Bit 15
[HEC Activation]
Bit 14
Indicates that HEC Functionality is either active or
inactive on the device’s HDMI output.
14{[HEC Activation]}
Bits
13-0
Indicates that HEC Functionality is either active or
inactive on the respective HDMI input. HDMI 1 shall
be indicated in bit 13 and HDMI 14 shall be indicated
in the LSB (bit 0). The HDMI input number shall be
defined to correspond to the respective physical
address of the appropriate HDMI input. Note that the
HDMI input number may be different in comparison
to the label printed near the connector.
“HEC Not Supported”
0
[HEC Activation]
[HEC Activation Field]
[HEC Support]
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Length
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Purpose
2 bits
1 bit
Indicates that HEC Functionality is inactive.
Indicates that HEC Functionality is active.
2 bytes
1 bit
Reserved (shall be set to 0)
Indicates that HEC Functionality is not supported.
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High-Definition Multimedia Interface Specification
Name
[HEC Support Field]
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Version 1.4b
Range Description
Length
Purpose
“HEC Supported”
1
“Reserved (0x0)”
Bit 15
[HEC Support]
Bit 14
Indicates that HEC Functionality is either supported
or not supported on the device’s HDMI output.
14{[HEC Support]}
Bits
13-0
Indicates that HEC Functionality is either supported
or not supported on the respective HDMI input.
HDMI 1 shall be indicated in bit 13 and HDMI 14
shall be indicated in the LSB (bit 0). The HDMI input
number shall be defined to correspond to the
respective physical address of the appropriate HDMI
input. Note that the HDMI input number may be
different in comparison to the label printed near the
connector.
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Indicates that HEC Functionality is supported.
2 bytes
Reserved (shall be set to 0)
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High-Definition Multimedia Interface Specification
Name
Version 1.4b
Range Description
[HEC State]
[HEC Functionality State]
[Host Functionality State]
[ENC Functionality State]
[HEC Set State]
[Input port number]
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Length
[HEC Functionality State]
[Host Functionality State]
[ENC Functionality State]
[CDC Error Code]
Purpose
1 byte
“HEC Not Supported”
0
“HEC Inactive”
1
Indicates that HEC Functionality is supported but
inactive
“HEC Active”
2
Indicates that HEC Functionality is supported and
active
“HEC Activation Field”
3
Indicates that HEC Functionality is supported and
active on at least one HDMI port. The activation
state of each HDMI port is indicated in the [HEC
Activation Field] parameter. This value shall only be
used in response to a <CDC_HEC_SetState>
message containing multiple VHECs.
“Host Not Supported”
0
“Host Inactive”
1
Indicates that Host Functionality is supported but
inactive
“Host Active”
2
Indicates that Host Functionality is supported and
active
“Ext Con Not Supported”
0
“Ext Con Inactive”
1
Indicates that an External Network Connection is
supported but inactive
“Ext Con Active”
2
Indicates that an External Network Connection is
supported and active
“Deactivate HEC”
0
“Activate HEC”
1
Initiator’s (Sink’s) input Port number
0≤N≤
15
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2 bits
2 bits
2 bits
Indicates that HEC Functionality is not supported
Indicates that Host Functionality is not supported
Indicates that an External Network Connection is not
supported (e.g. no cable connected)
1 byte
Sets the required HEC Functionality state of the
HDMI Ethernet Channel
4 bits
The value of the nibble of the Initiator’s physical
address that is different in the directly connected
Follower’s physical address.
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High-Definition Multimedia Interface Specification
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Name
Range Description
[HPD_State]
“CP&EDID_DISABLE”
0x0
“CP&EDID_ENABLE”
0x1
Indicates CP&EDID_MODE transition to Enabled
state
“CP&EDID_DISABLE_ENABLE”
0x2
Indicate CP&EDID_MODE transitions first to the
Disabled state then back to the Enabled state
“EDID_DISABLE”
0x3
Indicates EDID_MODE transition to Disabled state.
“EDID_ENABLE”
0x4
Indicates EDID_MODE transition to Enabled state.
“EDID_DISABLE_ENABLE”
0x5
Indicate EDID_MODE transitions first to the
Disabled state then back to the Enabled state
Reserved
0x6 - 0xF
“No Error”
0x0
“Initiator does not have the requested
Capability”
0x1
The device never supports this
Capability
“Initiator is not capable to carry out the
request in this state”
0x2
The device supports this Capability, but
is not capable to carry out the request
in the current state
[CDC_HPD_Error_Code]
Length
Purpose
4 bits
Indicates CP&EDID_MODE transition to Disabled
state
4 bits
Same
Range as
[CDC
Error
Code]
Note: A Source shall not use this
parameter
HDMI Licensing, LLC
“Other Error”
0x3
Another error occurred.
“No Error, No Video Stream”
0x4
“No Error” response with additional indication that
the Source is not sending a video stream
Reserved
0x5 – 0xF
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High-Definition Multimedia Interface Specification
Version 1.4b
HEAC 4
Audio Return Channel
HEAC 4.1
Overview
The Audio Return Channel function allows delivery of a single IEC 60958-1 stream from an HDMI Sink to an
adjacent HDMI Source/Repeater in the reverse direction to the TMDS signal (See HEAC 2) after negotiation
using CEC Audio Return Channel Control (see CEC 13.17).
e.g. TV
e.g. Audio Amplifier
TMDS signal
HDMI
HDMI Source
Repeater
(HDMI
(HDMI Repeater)
Source)
HDMI Sink
CEC
Audio Return Channel
HEAC Figure 4-1 Audio Return Channel Overview
Typically, the Audio Return Channel function is used as a connection between a TV (HDMI Sink) and an audio
Amplifier (HDMI Source/Repeater) to deliver an audio signal from the TV to the audio Amplifier, in conjunction
with using the CEC System Audio Control Feature (see CEC 13.15).
HEAC 4.2
Relationship with IEC 60958/IEC 61937
The interface format of the Audio Return Channel is defined in IEC 60958-1.This IEC 60958-1 stream also
shall comply with IEC 60958-3 or IEC 61937 specifications.
NOTE: Supplement 2 specifies a different physical specification from IEC 60958-1. (See Section HEAC 2)
Transmitted audio shall have an audio sample rate (fS) within ±1000 ppm of the sample rate indicated in
Channel Status bits 24 through 27 of IEC 60958-3.
NOTE: the allowed rate values do not include the IEC 60958-3 specified “Sample frequency not indicated”
value.
An HDMI device that has an Audio Return Channel receiver function shall support two- channel 16-bit L-PCM
audio at sample rates of 32 kHz, 44.1 kHz, and 48 kHz defined in IEC 60958-3 on the ARC connection.
An HDMI device that has an Audio Return Channel transmitter function shall support two-channel 16-bit
L-PCM audio at least one of these sample rates on the ARC connection.
NOTE: Clock frequencies correspond, respectively, to 4.096MHz, 5.6448MHz, and 6.144MHz.
Support of other audio formats as defined in IEC 60958-3 or compressed audio as defined in IEC 61937 (all
parts) is optional. CEC messages may be used to discover the supported audio formats, see section CEC
13.15.3.
HEAC 4.3
Functionality
In order to use the Audio Return Channel feature, it is necessary to discover and control the capabilities of the
devices in the respective paths, using CEC (Supplement 1). An Audio Return Channel device shall support
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CEC and shall not utilize audio data transmissions via the Audio Return Channel towards any HDMI devices
without the procedures specified in CEC 13.17. The discovery and control are identical for ARC common
mode transmission and ARC single mode transmission, and performed with no discrimination between both
modes.
The CEC messages activate or de-activate the Audio Return Channel and may enable power control of the
Audio Return Channel transmitter (ARC Tx) and receiver (ARC Rx). When the Audio Return Channel is
de-activated, the ARC Tx device and/or ARC Rx device may power down their ARC-related functionalities.
In the case where the ARC Tx device detects that the ARC Rx device has been unplugged from the ARC Tx
device, the ARC Tx device shall stop audio data transmissions via the Audio Return Channel and deactivate
its ARC Tx functionality on the port to which that ARC Rx device was connected.
The ARC Tx device is allowed to stop sending its audio signal via the Audio Return Channel temporarily while
keeping the link active. The ARC Rx device should take appropriate measures to prevent an undesired noise
on its audio output.
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High-Definition Multimedia Interface Specification
HEAC 5
Version 1.4b
Networking
Note: In this section, HEC means a bidirectional, full duplex, high speed differential transmission technology,
which does not include common mode transmission. In addition, an HEC output means an HDMI output
connector with HEC functionality. Likewise, a HEC input means the HDMI input connector with HEC
functionality.
HEAC 5.1
Relationship Between HEC and 100Base-TX
Except for the following items, the physical layer of the HEC system is compatible with 100 Base-TX [4n]:
- Full duplex mode exclusively:
Unnecessary to support CSMA/CD
- 100Mbps exclusively:
No negotiation with 10Mbps and other transfer speeds.
- Different Physical Medium:
A single pair of shielded twisted lines and hybrid circuits are used instead of two unshielded twisted
pair lines.
- Different MDI:
The RJ-45 connector is replaced by repurposing a pair of pins within the HDMI connector.
HEAC 5.2
Layer Architecture
HEAC Figure 5-1 shows the relationship between the Open System Interconnection (OSI) 7-layer reference
model, IEEE 802.3 standard (Ethernet) and HEC Physical layer.
Layer OSI 7-layer
reference model
no.
7
Application Layer
6
5
4
3
Presentation Layer
Session Layer
Transport Layer
Network Layer
Logical Link Control
Data Link
（ LLC）
Layer
Media Access Control
（ MAC）
2
1
Physical Layer
IEEE802.2
LLC
MAC
IEEE
802.3
CSMA/CD
MII
PHY
PCS
PMA
PMD
MDI
MEDIUM
100Base-TX
IEEE802.3u
HEC
Physical
HEAC Figure 5-1 Layer Architecture
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High-Definition Multimedia Interface Specification
HEAC 5.3
Version 1.4b
Network Topology
The HEC network topology is star-type topology. HEAC Figure 5-2 illustrates a HEC network consisting of
Sink, Repeater and Source devices interconnected by HEAC cables.
In this example, the devices are connected to each other; however there is no connection to a home network
via wired Ethernet using RJ-45 connectors or to a wireless network like 802.11a/b/g. An example connection
to a home network is shown later.
As precisely defined in HEAC 5.5, Sink, Repeater or Source devices which have at least two HEC connectors
shall have an internal Layer 2 switch for forwarding the MAC frames (HEAC Appendix A) between its ports.
Note: the optional MAC layer is shown in the dashed-line boxes in HEAC Figure 5-2 through HEAC Figure 5-6.
MAC
Sink
L2
SW
TV
HEC
MAC
Repeater
Amp
L2
SW
HEC
Source
MAC
MAC
HDR1
HDR2
PHY(HEC)
MII
HEAC Figure 5-2 Example of an HEC Network
HEAC 5.4
HEC Device Types
The following four types of HEC devices are identified with regard to network termination.
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Type e1:
HEC device with a single HEC input or output port and no network connection
Type e2:
HEC device with multiple HEC input and/or output ports and no network connection
Type e3:
HEC device with multiple HEC input and/or output ports and one or more network
connection(s)
Type e4:
HEC device with a single or multiple HEC ports and one or more other network connections,
and no forwarding of MAC frames from the HEC port(s) to the other network connections (e.g.
RJ45)
HEC output
MAC
MAC
L2
SW
HEC
HEC output
RJ-45 / 802.11 / PLC, etc.
MAC
MAC
Type e1
L2
SW
HEC
Type e2
Type e1
HEC input
PHY(802.3u)
PHY(HEC)
Type e2
MAC
or
RJ-45, etc.
MAC
L2
SW
HEC input
MAC
RJ-45, etc.
Type e3
MII
HEC
Type e4
HEAC Figure 5-3 HEC Device Types
HEAC 5.5
Ethernet Switching Functionality
All HEC device types that have multiple HEC input and/or output ports and no network connection (Type e2),
or multiple HEC input and/or output ports and one or more network connection(s) (Type e3), shall have a L2
SW which performs Ethernet switching functionality conforming to IEEE standards [4n] [5n] [6n]. Type e4
devices that have at least two HEC ports (see note below) shall have a L2 SW which performs Ethernet
switching functionality between the HEC ports.
Ethernet switching functionality is briefly summarized as follows: Refer to [5n]
1. acquire the source address of an incoming MAC frame and the port number from where the MAC frame
was sent.
2. search the filtering database for the destination address of the MAC frame and port number.
- case1: if the MAC frame destination address does not exist within the filtering database, then forward
the MAC frame to every port except to the port from where the MAC frame was sent.
- case2: if the MAC frame destination address exists within the filtering database with a different port
number, then forward the MAC frame to that port number (the different port number).
- case 3: if the MAC frame destination address and port number exists within the filtering database, then
filter the MAC frame.
3. the MAC frame's acquired source address and port number is registered with the filtering database.
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Note that Ethernet switching functionality is mandatory for all Type e2 devices, Type e3 devices, and Type e4
devices with at least two HEC ports. For a Type e4 device with at least two HEC ports, Ethernet switching
functionality is required between HEC ports but not from the HEC ports to the one or more network connection.
If forwarding of MAC frames between these connections is added to a Type e4 device, this device then
becomes a Type e3 device and Ethernet switching is then required.
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High-Definition Multimedia Interface Specification
HEAC 5.6
Version 1.4b
Connection to Internet via Home Network
HEAC Figure 5-4 shows an example of a HEC network which is connected to the Internet via the Home
Network. The connection to the Home Network may be implemented on any HEC device. Refer to HEAC
Appendix D for recommendations related to connection to the Home Network and the Internet.
Home
Network
Internet
Gateway
RJ-45
MAC
Sink
TV
L2
SW
PHY(802.3u)
HEC
PHY(HEC)
MAC
Repeater
Amp
MII
L2
SW
HEC
HEC
Source
MAC
HDR1
MAC
HDR2
HEAC Figure 5-4 Example of a Connection to the Internet
HEAC 5.7
Loop Detection and Loop Removal
HEAC Figure 5-5 shows a situation where a network loop is formed. All HEC Sink, Repeater and Source
devices that have an external network connection ( e.g. RJ45, 802.11 or PLC) shall have loop detection and
loop removal functionality to prevent traffic loops. Details are described below.
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High-Definition Multimedia Interface Specification
Home
Network
Version 1.4b
Internet
Gateway
RJ-45
MAC
Sink
TV
Network Loop
L2
SW
HEC
RJ-45
PHY(802.3u)
MAC
Repeater
Amp
PHY(HEC)
MII
L2
SW
HEC
HEC
Source
MAC
HDR1
MAC
HDR2
HEAC Figure 5-5 Example of a Network Loop
HEAC 5.7.1
Loop Detection Requirements
HEC devices that simultaneously fulfill the following conditions shall have loop detection capability.
condition (a): has multiple HEC outputs, or have at least one HEC output and an Ethernet or equivalent
port (RJ45, 802.11, PLC, etc.).
condition (b): The MAC frame is forwarded from an HEC output port to another HEC output port or from an
HEC output port to an Ethernet or equivalent port or from an Ethernet or equivalent port to a HEC output
port.
These HEC devices shall also have a loop removal function. The loop removal function shall disable
forwarding MAC frames to ports that are part of a loop.
The following method shall be used for loop detection and automatic loop removal:
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High-Definition Multimedia Interface Specification
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- RSTP (Rapid Spanning Tree Protocol) [5n]
HEC devices that do not need to have loop detection capability and loop removal function, i.e. RSTP,
according to the rules above, shall anyway forward the RSTP BPDUs [5n] to enable correct loop detection and
loop removal operation in the system.
Note: if any (non-HEC) switches exist in the loop (e.g. as part of the home network) that do not forward RSTP
messages, then the RSTP is not fully functional and automatic loop detection and removal is not always
possible.
HEAC Figure 5-6 shows examples of an HEC Type e3 device that: in Case 1 meets the conditions requiring
loop detection capability; in Case 2 does not meet the conditions requiring loop detection capability; in Case 3
device does not have any HEAC output. In these examples, the assumption is the device transfers MAC
frames between each port (Type e3).
In these examples, Sum_O means the sum of the number of HEC outputs and the number of Ethernet or
equivalent ports (RJ45, 802.11, PLC, etc.)
Case 1: Sum_O of this Repeater is 2, so the Repeater shall have loop detection capability and loop
removal functionality.
Case 2: Sum_O of this Sink is 1, so the Sink does not need loop detection capability nor loop removal
functionality. However it shall forward the BPDUs to enable correct loop detection and loop removal
operation in other devices.
Case 3: Sum_O of this Sink is 2, and since this Sink does not have any HEC outputs, this case does not
satisfy all the conditions described above, however it is recommended to have the capability for loop
detection and removal functionality for such devices anyway.
HEC output
MAC
Repeater
MAC
Sink
Sink
L2
SW
L2
SW
MAC
L2
SW
HEC input
HEC input
Case 1: Sum_O = 2
RJ-45 / 802.11 / PLC, etc.
RJ-45 / 802.11 / PLC, etc.
RJ-45 / 802.11 / PLC, etc.
Case 2: Sum_O = 1
HEC input
Case 3: Sum_O = 2, but
no HEC output
HEAC Figure 5-6 Example of Three Device Cases with Respect to Conditions for Loop Detection and Removal Capability
HEAC 5.8
QoS
HEC uses conventional QoS mechanisms using VLAN priority tags (IEEE802.1Q [6n]) and queues.
For Ethernet packets which originate from outside the HEC network and which use VLAN Tag values, HEC
devices should pass through those Ethernet packets and should use the same VLAN tag values already
carried in those Ethernet packets. Ethernet packets which do not have VLAN tags shall be treated as best
effort (priority 0, default).
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For Ethernet packets which originate from within the HEC network, the mapping of traffic type or application
type to user priority is typically defined by the application, e.g., DLNA [1i] (see also HEAC Appendix B), DVB.
For Ethernet packets which originate within the HEC network and where there is no other applicable normative
standard or specification to define the VLAN tags, the application shall use the Tag values defined in HEAC
Appendix C.
The following functions shall be incorporated into each L2 switch within a HEC device for QoS control.
- Four or more queues for egress service
- Support for the MAC frame format with priority tags (See HEAC Appendix A)
The user priority is expressed by 3 bits in the TCI (Tag Control Information). The user priority to Ethernet
packets class mapping defined in Table 7-2 in IEEE 802.1D [5n] shall be applied in the L2 switch.
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High-Definition Multimedia Interface Specification
HEAC 6
Version 1.4b
Appendices
HEAC Appendix A MAC Frame Format (Informative)
HEAC Figure 6-1 shows the MAC frame format (Fig 3-3 in IEEE802.3 [4n]) with tagging (IEEE802.1Q [6n]).
HEAC Figure 6-1 MAC Frame Format
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HEAC Appendix B User Priority with Respect to Traffic Class Mapping
(Informative)
HEAC Figure 6-2 shows the example of Traffic type to User priority to Traffic class mapping with four queues
for DLNA. For other applications, Traffic type to User priority mapping may be different. It depends upon each
application.
HEAC Figure 6-2 An Example of DLNA User Priority for Traffic Class Mapping
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HEAC Appendix C User Priority with Respect to Traffic Type Mapping
If priority tagging for an application is not already specified by another standard or specification, then user
priority which does not exceed the value in HEAC Table 6-1 shall be used.
HEAC Table 6-1 HEC Mapping for User Priority Traffic Type
Traffic Type or
User Priority
Application Type
Control
7
A/V Streaming
5
Data Services
2
Best Effort
0
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HEAC Appendix D Connection to the Home Network and Internet
HEAC Figure 6-3 shows two examples of HEC networks which are connected to the Internet and to each other
via the Home Network.
To provide for uplink connection and Layer 2 switching to the Home Network and Internet, it is recommended
that HEC devices with two or more HEC ports support a minimum of one external network port. In the
examples in HEAC Figure 6-3, the amplifier is shown with 5 HEC ports and the TV with 4 HEC ports, with each
of these devices including an RJ45 external network port.
HEAC Figure 6-3 Examples of Connection to the Home Network and Internet
In the HEC network example without amplifier on the right side of HEAC Figure 6-3, the external port
connection to the Home Network and Internet may be accessed by all HEC devices simultaneously. Each
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HEC port (labeled 1 to 4) is capable of 100Mbps in each direction for an aggregate directional bandwidth of
400Mbps. To avoid uplink bandwidth congestion, it is recommended that the external port (and its associated
internal switching logic) supports sufficient connection bandwidth to aggregate the bandwidth demands of the
HEC ports:
N
Upstream bandwidth
HEC port(i)
i=1
The device’s internal host bandwidth requirements for the uplink should additionally be taken into account.
In the HEC network example including amplifier on the left side of HEAC Figure 5-4, this recommendation
indicates for the amplifier to include an external port with a minimum directional bandwidth of 0.5Gbps to
aggregate the HEC ports (labeled 1 to 5). By example, the criteria can be met by inclusion of a Gigabit
Ethernet external network port. For this HEC network example, the connection to the Home Network and
Internet is made from the amplifier to avoid the 100Mbps bandwidth limitation of the amplifier-to-TV HEC
connection that would result if the TV uplink connection would have been used.
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